after its completion, the fortress was a part of the inner system of fortifications that protected the outer regions of the empire, for possible conflicts in the area, as with the oradea and timișoara fortifications. starting from 1794, the fortress has been used as a military prison when 1200 french soldiers were imprisoned. during the 1848–1849 revolution, the fortress played a key role as it was besieged by the hungarian republican army for nine months until it was finally occupied in june 1849. after only 46 days, the habsburg army moved back into the fortress and used it partly as a military prison for more than 500 officers. most of the prisoners were sentenced to death. among them were the 13 generals of the republican army that were executed on october 6, outside the outer east walls of the fortress, and today are considered martyrs.