EDELMAN J.
Introduction
This appeal involves several different legal rules concerned with finality of litigation, variously described as res judicata, cause of action estoppel, issue estoppel, and Anshun estoppel. The English translations of the Latin "res judicata" ("a thing decided") and the Norman French "estoppel" ("stopper, bung"), and a doctrine named after a case, do not provide much assistance in understanding the different legal rules. But when the dust is cleared from the different legal rules, a single and simple question arises on this appeal.
Ms Clayton and Mr Bant (both pseudonyms) were married in Dubai in 2007. Mr Bant owns considerable property in the United Arab Emirates, Paris, Jordan, Thailand and Australia. Ms Clayton owns personal property in Dubai and real property in Australia. They separated in 2013, following which Ms Clayton resided in Australia with their child. In July 2013, Ms Clayton sought property settlement and spousal maintenance orders in Australia as part of an extant application for parenting orders; and in September 2014 she commenced divorce proceedings in Australia. In June 2014, Mr Bant lodged caveats over two properties owned by Ms Clayton in Australia; and in July 2014, Mr Bant commenced divorce proceedings in Dubai. Ms Clayton did not take part in the Dubai proceedings.
In February 2015, the Second Personal Status Family Circuit of the Dubai Court delivered judgment and made orders in the Dubai proceedings. Mr Bant was granted an "irrevocable fault-based divorce", with Ms Clayton ordered to pay his costs and to repay an "advanced dowry" which Mr Bant had paid to her on formation of the contract of marriage. Under the Personal Status Law of the United Arab Emirates (Federal Law No 28 of 2005 on Personal Status), the Dubai Court had no jurisdiction with respect to property outside the territory of the Emirate and the Personal Status Law made no provision for the redistribution of any property anywhere in the world.
When the different finality doctrines are separated, and their principles understood, the main point in this appeal can be seen to concern whether Ms Clayton's property settlement and spousal maintenance proceedings are barred because they fall within the character of a claim that was pursued and decided by the Dubai Court. That point reduces to a simple question: should Mr Bant's claim, as resolved by the Dubai Court, be characterised as a claim merely for dissolution of the marriage or should it be characterised as a claim for dissolution of the marriage and resolution of all the financial consequences of the marriage including distribution of the property of the parties? The proper characterisation is that the claim resolved by the Dubai Court was only for the dissolution of the marriage. Ms Clayton can maintain proceedings in Australia under the Family Law Act 1975 (Cth) for property settlement and spousal maintenance.
Four relevant rules of finality
Four rules concerning finality are relevant to this appeal. Although the principle of finality underlies all of them, and although each rule can apply where there is a final judgment on the merits by a court of competent jurisdiction, the four rules should be kept separate.
Merger or res judicata in the strict sense
First, where a cause of action, or "the very right ... claimed", has previously been established by a local court then at common law the "merger of the right or obligation in the judgment" can be relied upon to preclude re-assertion of the extinguished right. The doctrine of merger is not merely based upon principles of finality. It exists because when a court order "replicates" the prior right, with added consequences such as enforcement mechanisms, the prior right "has no longer an independent existence". No action can be brought upon that extinguished right. The successful plaintiff's only right is a right on the local judgment, which is "of a higher nature". Since the expression "res judicata" has also been loosely used to describe all four rules discussed below, each of which is underpinned by a policy of finality, the effect of the doctrine of merger is sometimes described as "res judicata in the strict sense".
Cause of action or claim estoppel
Secondly, if the judgment finally resolved a conflict about the existence or extent of a "cause of action" then the parties to that proceeding, or their privies, will be precluded from relitigating that cause of action. This rule is independent of the doctrine of merger because even if the rights adjudicated upon were determined not to exist in the earlier proceeding, so that there was nothing to merge into the judgment, "the unsuccessful plaintiff can no longer assert" that a right exists. The Full Court of the Family Court of Australia in this proceeding described the rule as "res judicata estoppel". In Australia, it is usually described as "cause of action estoppel". But, as has been pointed out on a number of occasions, the expression "cause of action" is imprecise and might extend either to the legal right claimed or to the facts that the plaintiff must establish for their claim.
The best approach is to recognise that both the legal right claimed and decided and the pleaded or asserted facts are relevant: "cause of action normally means a right alleged to flow from the facts pleaded". The focus is upon the whole claim, including the right and the essential facts upon which the right depends. But much can depend upon the level of generality at which the claim is characterised. As Gummow J said in Trawl Industries of Australia Pty Ltd (In liq) v Effem Foods Pty Ltd, characterisation must proceed by reference to substance rather than form. Regard can be had to the pleadings, the evidence, and the reasons for decision.
Issue estoppel
Thirdly, if a necessary legal foundation for the judgment is the resolution of an ultimate issue of fact or law then the parties or their privies are precluded from alleging or denying a state of fact or law that is inconsistent with that resolution. This rule is well known by the description "issue estoppel", which was first coined by Higgins J. The same issues of characterisation arise in respect of an issue for issue estoppel as arise in respect of a claim for cause of action or claim estoppel.
Anshun estoppel or the extended principle in Henderson v Henderson
Fourthly, there is an extension of the second and third rules. A party will be precluded from relying upon a cause of action (within the meaning of the second rule) or an issue (within the meaning of the third rule) if it "was so relevant to the subject matter of the first action that it would have been unreasonable not to rely on it". This fourth rule, which was recognised in England in Henderson v Henderson and in Australia in Port of Melbourne Authority v Anshun Pty Ltd, is commonly described as the extended principle in Henderson v Henderson or as Anshun estoppel.
Res judicata and "cause of action" or "claim" estoppel in this appeal
The first ground of Ms Clayton's appeal to this Court alleged that the Full Court had erred in finding that the claims for property settlement and spousal maintenance had merged in the Dubai decree or that the Dubai decree had finally determined such claims between the parties. Although the Full Court relied upon the "cause of action estoppel" rule rather than the rule of merger, the reliance upon merger in Ms Clayton's ground of appeal might have been due to a view that was taken of remarks in the joint judgment in Tomlinson v Ramsey Food Processing Pty Ltd which suggested that a cause of action estoppel is "largely redundant" in the field of exercise of judicial power because the field is covered by res judicata in the strict sense of merger. Those remarks, however, should not be understood as suggesting that cause of action estoppel is co-extensive with the doctrine of merger or that there is not a sphere, perhaps even a significant sphere, of operation for cause of action estoppel. Cause of action estoppel remains important and the two rules must be kept separate in order to avoid "[m]uch confusion".
The Full Court did not rely upon res judicata in the strict sense of merger of the successful plaintiff's rights into the rights arising on the judgment. It could not have done so. Rights that are recognised in a local jurisdiction, such as Australia, do not merge into the final judgment of a foreign jurisdiction, such as the United Arab Emirates, even where the foreign judgment is based upon the same facts as those that support the right in Australia. By contrast, it was common ground that a cause of action estoppel can arise from a foreign judgment.
Ms Clayton's second ground of appeal extended beyond the doctrine of merger and relied also upon "cause of action estoppel" and "the Henderson extension". Ms Clayton's submissions on cause of action or claim estoppel were based upon the assertion that the Full Court erred in holding that the estoppel precluded her from prosecuting her case under s 79 of the Family Law Act. She asserted that cause of action estoppel could not apply because the Dubai Court had no jurisdiction over property outside Dubai and the only extent to which she could have sought an adjustment of property was under Art 62.1 of the Personal Status Law.
Mr Bant's claim in the Dubai Court was as follows:
"Second: Divorce the plaintiff from the defendant, dropping all her marital rights that are associated with that divorce in terms of all type of alimony, deferred dowry and others as well as compensating him for all material and moral damage at the discretion of the Court and to observe all the plaintiff's other rights".
In order to appreciate the nature of this claim, to which the Dubai Court responded with its ruling granting a fault-based divorce and ordering repayment of the dowry, the starting point is the lack of any jurisdiction for the Dubai Court to make orders for redistribution of the parties' property. The only possible candidate for such jurisdiction was Art 62.1. But that provision does not empower any redistribution of property. It provides:
"A woman having reached the age of full capacity is free to dispose of her property and the husband may not, without her consent, dispose thereof; each one of them has independent financial assets. If one of the two participates with the other in the development of a property, building a dwelling place or the like, he may claim from the latter his share therein upon divorce or death."
Article 62.1 might loosely be described, as the Full Court described it, as involving an "adjustment of property" or, more accurately, a distribution of rights to existing property. But, as the primary judge correctly concluded, although a party can establish an existing share based upon financial contribution in order to "displace a presumption of joint ownership", the law of Dubai does not accord the parties with any rights to redistribution of property that are analogous to s 79 of the Family Law Act. The experts had agreed that there was no provision in Dubai for redistribution of assets as understood in Australia, although one of them had analogised a claim based on financial contribution with rights based on the rules and principles of equity.
The application of cause of action or claim estoppel reduces here to the question of characterisation. As explained above, the question of characterisation is one of substance, not form, and much will depend upon the level of generality at which the claim is characterised. For instance, a cause of action or claim estoppel barred a claim for compensation for negligent misrepresentation after an earlier, facially different, misleading or deceptive conduct claim under s 52 of the Trade Practices Act 1974 (Cth) was characterised at a higher level of generality as a claim for recovery of loss flowing from the defendant's acts: "how much worse off is [the plaintiff] as a consequence of the acts and omissions of [the defendant]?"
Mr Bant's submission was effectively that the orders of the Dubai Court should be characterised as having decided a cause of action, or claim, for dissolution of the marriage and all of its financial consequences. On that submission, the absence of any law in Dubai concerning redistribution of property upon divorce leaves property rights where they lay and is merely a different approach to adjudicating the claim or controversy. By contrast, Ms Clayton's submission was effectively that Mr Bant's cause of action, or claim, should be characterised more narrowly, involving only the dissolution of the marriage and immediately related matters such as repayment of the dowry paid under the marriage contract.
In many, possibly most, cases a prior final judicial adjudication upon the dissolution of marriage will be characterised as including all of the consequences, including distribution of property, that flow from the dissolution. As this Court said in Henry v Henry:
"differences in procedure, in available remedies and in the substantive law with respect to marriage and divorce will ordinarily ensure that the proceedings are different in significant respects. However, the proceedings will ordinarily be concerned with the same controversy ... [I]t is the marital relationship itself which is the subject of controversy ... [D]isputes with respect to property, maintenance and the custody of children will ordinarily be but aspects of an underlying controversy with respect to the marital relationship."
That characterisation will ordinarily apply even where, as the Full Court correctly held in In the Marriage of Caddy and Miller, different legal rules in the foreign proceedings might lead to different recovery such as the mandated equal division of property by Californian law in that case. But this is not an ordinary case.
Mr Bant's claim in the Dubai Court is best characterised as one for the dissolution of marriage only. The expert evidence was not that the Personal Status Law had adopted a rule requiring maintenance of existing property rights before marriage. Rather, the expert evidence was that the Dubai Court had no jurisdiction with respect to property outside the territory of the Emirate. The lack of any rule for redistribution of assets, within or outside the Emirate, follows naturally from this lack of jurisdiction, since any redistribution of property within the Emirate might be expected to take into account respective foreign property holdings of the parties. No cause of action or claim estoppel can bar Ms Clayton's claim for a redistribution of property rights under s 79 of the Family Law Act.
Issue estoppel and Anshun estoppel in this appeal
The Full Court also relied upon Anshun estoppel to conclude that Ms Clayton's claim for a redistribution of property rights under s 79 of the Family Law Act was barred. In his oral submissions in this Court, however, senior counsel for Mr Bant properly accepted that an Anshun estoppel could not apply because it could never be unreasonable to fail to claim that which was not available.
The remaining matter is the conclusion of the Full Court that Ms Clayton was barred from bringing a claim for spousal maintenance in the Family Court of Australia because "the issue was finally heard and determined" by the Dubai Court and she "cannot now bring a claim for spouse maintenance by operation of the 'Henderson extension'". This reasoning requires Mr Bant's claim in the Dubai Court to be characterised as extending beyond the mere dissolution of marriage to include also financial consequences of alimony, on the basis that this is equivalent to maintenance.
Although Mr Bant's claim in the Dubai Court included a claim for Ms Clayton "dropping all her marital rights that are associated with that divorce in terms of all type of alimony", the expert opinion concerning the nature and effect of alimony in the Personal Status Law was not provided to this Court in the appeal books. It is unclear, for instance, the extent to which alimony can be ordered beyond the time at which a divorce is made final, although one Article, concerned with the "waiting period" before a "non retractable" divorce, prevents payment of alimony, but not "sheltering", if the divorced woman is not pregnant. Nor is it clear how the provisions for alimony for children should be applied. In the absence of expert evidence, this Court cannot interpret the Personal Status Law according to its own background understanding or rules of interpretation. The only conclusions that can be drawn about alimony are those unchallenged findings of the primary judge that "alimony to a wife is forfeited ... if she abandons her home", as was considered by the Dubai Court to be the case, but that alimony in addition to that payable during the "waiting period" would have been payable to Ms Clayton if Mr Bant had divorced her "on a basis other than that advanced to the Dubai Court".
The Dubai Court ruled that the subject of Mr Bant's claim to "drop off" all of Ms Clayton's rights to alimony and deferred dowry "is untimely", adding that Ms Clayton "did not demand them and hence there is no need to make reference to them in the text". The natural understanding of this English translation is that the Court considered that Mr Bant's claim to exclude any of Ms Clayton's rights to alimony was premature and would be decided at a future time if there were a need to do so. As the primary judge concluded, the issue was not dealt with by the Dubai Court. Although the Full Court considered that the issue had been "finally heard and determined", no basis was given for that reasoning, in the expert evidence or otherwise.
An issue that has not been considered cannot be the subject of an issue estoppel, nor can it be the subject of an Anshun estoppel if it remains open to be determined at a future time.
Conclusion
The appeal should be allowed with costs. Orders 2, 3, and 4 of the Full Court of the Family Court should be set aside and in their place it should be ordered that the appeal be dismissed. The appellant did not seek to disturb either the order of the Full Court granting the respondent leave to appeal (order 1) or the costs orders made by the Full Court (orders 5, 6, and 7).
Although this stay application has involved expert evidence and legal issues of some complexity, and although all courts have produced carefully reasoned judgments, it is unfortunate that there has been a delay of approximately five years between the hearing of the stay application by the primary judge and its final resolution in this Court. This remark is made to emphasise the need for expedition of this proceeding but not to cast any aspersion upon the thorough and thoughtful judgments, or the time taken to produce them, by all the Family Court judges involved in this proceeding. Although delay usually causes injustice, mere delay does not imply fault or blame on any court or decision maker. Reasons for delay, which were not the subject of question or comment during the hearing of this appeal, can be multifarious. They might include unavoidable personal issues confronted by the decision maker. They might include institutional reasons such as heavy case loads and backlogs. Or they might relate to the manner in which the parties have conducted the litigation in light of the usual processes of the court. Indeed, there was a very similar appellate delay between, on the one hand, the institution of the appeal in the Full Court of the Family Court and the delivery of reasons (during which period the Full Court of the Family Court also heard and resolved other disputes between the same parties) and, on the other hand, the application for special leave in this Court and the delivery of this Court's reasons.