The foundations for the later empire of Austria-Hungary were laid in 1515 by the means of a double wedding between Louis, only son of Vladislaus II, King of Bohemia and Hungary, and Maximilian's granddaughter Mary; and between her brother Archduke Ferdinand and Louis's sister Anna. The wedding was celebrated in grand style on . All these children were still minors, so the wedding was formally completed in 1521. Vladislaus died on 13 March 1516, and Maximilian died on 12 January 1519, but the latter's designs were ultimately successful: upon Louis's death in battle in 1526, Ferdinand became king of Bohemia and Hungary.