sentence1: The fortress was once again besieged by Bavarian troops under the command of General Zoller , from 22 December 1813 to 14 April 1814 , before the French garrison capitulated .
sentence2: The fortress was besieged again from 22 December 1813 until 14 April 1814 by Bavarian troops under the command of General Zoller before the French garrison surrendered .