Proving Iranian law
Foreign law misapplied. What can you do with it?

The verdict stands. It is based on Iranian inheritance law. You think the interpretation is wrong, and you are right.
But that doesn't help you in Karlsruhe.
Foreign law itself is not subject to review
Even after the new version of Section 545 (1) of the Code of Civil Procedure, this remains the case (Federal Court of Justice, decision of 4.7.2013, V ZB 197/12, BGHZ 198, 14). Pursuant to Section 560 of the Code of Civil Procedure, the court hearing the appeal on points of law is bound by the findings of the lower court on the existence and content of the foreign law. The interpretation as such is no longer up for debate there.
It is the determination
An erroneous determination of foreign law can be challenged with the procedural objection based on Section 293 of the Code of Civil Procedure. Not the result, but the way to get there. This is exactly where judgments are broken.
The scale
The investigation must not be limited to the use of the sources of law. It must take into account the specific design of the law in foreign legal practice, in particular the case law there. The German judge must apply the foreign law in the same way as the judge of that country interprets and applies it, and in doing so exhaust the sources of information available to him.
A legal text with a translation does not meet this standard.
The stranger, the stricter
The more complex and the more alien the applicable law is compared to the German law, the higher the requirements to be placed on the duty to investigate. In the case of a related legal system with clear norms, the bar is lowered. With a distant one, it rises.
And the costs
The fact that an expert opinion will cost many times the amount in dispute is not in itself a reason to refrain from doing so (Federal Court of Justice, judgment of 14.1.2014, II ZR 192/13).
In practice, this means two things. Anyone who wants to challenge a judgment first examines what the court has based its knowledge of the foreign law on. And anyone who wants to defend one makes sure that it is visible in the reasons that more than the text of the law has been evaluated.
One legal system alone is never enough.
##IPR ZPO Revision AuslaendischesRecht Erbrecht Familienrecht Prozessrecht Sachverstaendiger Gutachten BGH Verfahrensrecht CrossBorder Nachlass Iran