When Peter the Great re-conquered the lands along the Neva river in 1703, he started the construction of a fort to protect the area from possible attack by the Swedish. The Fortress was founded on a small island in the Neva Delta on May 27,1703. The Swedes were defeated before the Fortress was even completed. For that reason, the Fortress housed part of the city's garrison and rather notoriously served as a high security political jail. After the death of Peter the Great its Cathedral was turned into the cemetery for the Royal Dynasty of the Romanovs.