If you were married abroad and one of you is a German citizen, you can have your marriage registered in Germany.
German citizenship is determined as of the date the application is filed.
Stateless persons, stateless foreigners, or foreign refugees with habitual residence in Germany may also apply to have their marriage registered retroactively.
The marriage must have been entered into in accordance with the formal requirements applicable in the country where you were married. German law must not preclude the marriage.
You may also have your marriage retroactively registered if neither of you holds German citizenship and you were married in Germany before an authorized official of the government of the country to which one of you belongs.
The registry office responsible for the subsequent registration is the one in your place of residence, the place where you last resided, or the place of your habitual residence.
If your habitual residence is not in Germany, the Registry Office I in Berlin is responsible for the subsequent registration.