ENThe article “Lida Castle in the Period of the Great Duke Alexander” by a Belarusian historian and archaeologist Aleg Trusau narrates on the construction and history of one of the most fortified state-owned castles of the Great Duchy of Litva. The castle was built by the Great duke Gedymin in the early XIV century to be an important part of the defense line against the Teutonic Order. Lida castle is quadrangular. It is one of the largest Belarusian castles (the inner yard size is approximately 80 x 80 m.). It is built of field stones and large-sized brick and originally had one tetragonal tower (9x9 m.) in the South-Western comer. The castle had three gates. One of them was an emergency exit at a height of four meters above the ground. The North-Eastern tower was built during Vitaut reign, probably in 1394 - 1395. The designers took artillery capacity into consideration. Some historians consider that Vitaut’s ally khan Tochtamysh had lived in the castle for several years after 1396. The castle plays an important role both in the defense of the country and in the development of Lida town. Consequently, it was Lida were the Great Duke Alexander came on July 24 - 25, 1506, as soon as plundering raids of the Crimean Tatars began. Over there he summoned the Seim which was to legitimize the transfer of power from him (as far as Alexander was fatally ill) to his younger brother Sigismund. The peoples’ volunteer corps which later defeated the Tatars were assembled in the neighborhood of the castle.The unique material discovered and collected by the author during excavations at Lida castle (1977 - 1978,1980, 1985) gives quite a clear view of the material culture of the castle in the XVI - first half of the XVII centuries. Lida trade relations with Italian, Germany and Poland cities are evident. The castle suffered irremediable loss from the Russian troops which seized it and burned down in summer, 1659. The Swedes blew up the towers and the comers of the castle during the Northern war. The castle was ruined for good and all in summer, 1794, when Tadeusz Kościuszko’s rebels were standing the siege of the Russian troops. It has been in mins and deteriorated throughout the whole XIX century. Cosmetic alterations took place in 1909 and in the 1920-ies. Archaeological excavations started in 1970 and in 1975 the restoration began under the command of an architect Siarhej Baglasau. The North- Eastern tower had been restored up to 1986. However, the works were stopped in the mid 1990-ies for want of sponsorship and the castle began deteriorating again. The restoration has been recently recommenced by the town authorities. Lida castle is now a famous tourist attraction. “Gedymin Castle” medieval festival took place in the castle in September, 2005. The castle is conceptualized to become a multifunctional museum complex for the benefit of Lida dwellers, Belarusian and foreign tourists. The view of Lida castle is represented on a variety of postcards, booklets, envelopes and stamps of the Republic of Belams.