monastery was besieged by Polish-Lithuanian vagabonds, the Lisowczycy, who failed to capture it. Attractions The vast walled area of the monastery comprises two separate priories with eleven churches, most of them dating to the 16th century. Of these, nine belong to the Uspensky (Dormition, the Orthodox equivalent of the Catholic holiday known as the Assumption of Mary) priory by the lake. The Dormition cathedral, erected by Rostov masters in 1497, was the largest monastery church built in Russia up to that date. Its 17th-century iconostasis features many ancient icons, arranged in five tiers above a silver heaven gate endowed by Tsar Alexis in 1645. A lot of valuable objects kept in the sacristy are personal gifts of the tsars who visited the monastery. The smaller Ivanovsky priory is dedicated to St. John the Precursor, the patron saint of Ivan the Terrible. The oldest church of the priory was commissioned by Ivan's father, for the benefit of the "mendicant brethren," soon after his visit to the monastery in 1528. Subsequently, the monks incurred the tsar's displeasure by constructing St. Vladimir's Chapel over the grave of the exiled Prince Vorotynsky. Although the tsar chastised them for having broken canonical requirements, the chapel — which became the first family mausoleum in Russia — survived Ivan's reign and was expanded to its present form in 1623. The monastery walls, 732 meters long and 7 meters thick, were constructed in 1654-80. They incorporate parts of the earlier citadel, which helped to withstand the Polish siege in 1612. The first construction works were supervised by Jean de Gron, a French military engineer known in Russian sources as Anton Granovsky. After the monastic authorities denigrated his Western-style design as alien to Russian traditions, Granovsky was replaced by a team of native masters. The fortress was the largest erected in Muscovy after the Time of Troubles; its walls feature numerous towers, each built to a particular design. The most remarkable are the Chasuble, the Tent-like, the Vologda, and the Smithy towers. After secularisation After the Bolsheviks, the monastery was secularised and turned into a museum (1924), a wooden shrine from 1485 and several traditional timber structures were put on exhibit on the grounds. During Soviet restoration works, superb 16th-century frescoes were discovered in the gate church of St. Sergius (1560–94). On the other hand, the monastic library and some other treasures were transferred to Moscow and St Petersburg.