The appeal courts have repeatedly emphasised that a dissatisfied party seeking to overturn a finding of fact will face an uphill battle.
Central to this analysis is the trial judge’s role as the master of fact-finding. The trial judge carries out this role in an atmosphere and setting which simply cannot be recreated on an appeal.
The trial is therefore “not a dress rehearsal. It is the first and last night of the show”: see Fage UK Ltd & Anor v Chobani UK Ltd & Anor  EWCA Civ 5 at .
The courts often find themselves reminding litigants that foreign law is also a question of fact. But, as they usually go on to say, it is a question of fact “of a peculiar kind.”
What exactly does this mean when it comes to the principles that the courts will apply to appeals against findings of foreign law?
The Court of Appeal gave detailed consideration to exactly this issue in Byers & Ors v The Saudi National Bank  EWCA Civ 43.
The starting point, said Newey LJ, remains the warning in Fage that appeal courts will not usually intervene to overturn factual findings made by trial judges:
The FAGE approach remains the starting point in any appeal from such a determination of foreign law (ibid paragraph 36).
However, there is a qualification:
However it may be qualified, because a question of foreign law has been described as “a question of fact of a peculiar kind”: Parkasho v Singh  P 233, 250.
What difference does that qualification actually make?
This had been commented on specifically in MCC Proceeds Inc v Bishopsgate Investment Trust Plc & Ors  EWCA Civ 1680 at . Essentially, the answer varies depending on the type of evidence:
In our judgment, the answer varies according to the nature of the issue which arises in the particular case and the kind of decision which the trial judge and now the Court of Appeal is called upon to make.
Where the foreign law involves concepts unfamiliar to English lawyers, the trial judge will be less able to bring his or her own expertise to bear:
Sometimes the foreign law, apart from being in a foreign language, may involve principles and concepts which are unfamiliar to an English lawyer. The English judge’s training and experience in English law, therefore, can only make a limited contribution to his decision on the issue of foreign law.
But where the foreign law is very similar to English law, the trial judge’s own experience will have more relevance:
But the foreign law may be written in the English language; and its concepts may not be so different from English law. Then the English judge’s knowledge of the common law and of the rules of statutory construction cannot be left out of account. He is entitled and indeed bound to bring that part of his qualifications to bear on the issue which he has to decide, notwithstanding that it is an issue of foreign law. There is a legal input from him, in addition to the judicial task of assessing the weight of the evidence given.
An appeal court will more readily interfere in the second situation (involving concepts familiar to the English courts):
The same applies, in our judgment, in the Court of Appeal. When and to the extent that the issue calls for the exercise of legal judgment, by reference to principles and legal concepts which are familiar to an English lawyer, then the court is as well placed as the trial judge to form its own independent view.
Returning to Byers, Newey LJ in that case rejected an argument that, since the foreign law experts had agreed on the principles of construction of Saudi Arabian regulations, the appeal court was in as good a position to interpret them as the trial judge.
He started by repeating the general principles that the courts would apply in foreign law disputes. The focus was on working out how the relevant foreign court would approach the question:
Generally speaking the Court’s task is not to address how it would itself interpret and apply the provision; the wording of the provision is to be considered only as part of the evidence and as a help to decide between conflicting expert testimony …
This general rule was then subject to the qualification about foreign law concepts familiar to English lawyers described in the MCC case above (called Macmillan in the following quote):
There is a qualification to this general principle, recognised in Macmillan Inc v Bishopsgate Investment Trust (No 4), and applicable to a first instance Court as well as on appeal, where the nature of the foreign law issue means that the English Court’s expertise approaches that of any foreign law expert, for example where the foreign law is written in the English language and involves concepts similar to English law and familiar to English judges; or where the foreign Courts would be influenced by the English Courts’ decisions on the issue …
Ultimately, said Newey LJ, applying those principles, there was no scope for applying the qualification in Byers:
The only authorised texts of CMR and CR are in Arabic and the trial judge had to work from an agreed translation, albeit that in the case of CMR it was one published by the CMA. Saudi Arabian law is an Islamic system of law, whose concepts and principles are far removed from the common law familiar to English judges. The interpretation and application of CR and CMR fell to be determined not only under this unfamiliar system of law, but also against the background of practice and culture in the capital markets in Saudi Arabia, with which again the English Courts have no inherent familiarity.
It was particularly significant that the judge had needed the assistance of extensive expert evidence to “explain and explore” the many Saudi Arabian Court decisions relied on by both experts. In such circumstances:
It would have been both wrong in principle, and impossible in practice, for the Judge to approach the task as one of interpreting the provisions for himself as a matter of construction.
And this made the appeal court’s position clear:
It would be equally wrong for this Court to seek to do so. This is a case in which the FAGE approach applies: this Court should be slow to interfere with the Judge’s findings of fact on Saudi Arabian law and should only do so in accordance with the principles applicable generally to findings of fact made by a trial judge who has based his findings on evidence from witnesses.