Abstract
In 1532 Sultan Suleiman I was once again threatening the eastern reaches of the Habsburg monarchy. An army commanded by Emperor Charles V and his brother Ferdinand I was assembled to oppose him.
Before the offensive started on 17 September Ferdinand drew up a testament in which he regulated the succession. However, since Ferdinand was 'merely' the ruling king at the side of the actual heiress to the throne, he was unable to make any provisions for Bohemia and Hungary without Anna's participation.
Anna therefore herself issued a document on 9 September 1532 signing over all rights of succession to her sons, Maximilian and Ferdinand. Nonetheless, she retained for herself the regency in both kingdoms until her death in the event of Ferdinand I predeceasing her.