SANDOMIR, or SEDOMIERZ  , a town of Russian Poland, in the government of Radom, 140 M . S.S.E. of Warsaw by riverand on the left bank of the Vistula, opposite the confluence of the San . Pop . (1881) 6265, or, including suburbs, 14,710; (1897) 6534 . It is one of the oldest towns of Poland, being mentioned as early as 1079; from 1139 to 1332 it was the chief town of the principality of the same name . In 1240, and again in 1259, it was burned by the Mongols . Under Casimir III. it reached a high degree of prosperity . In 1429 it was the seat of a congress for the establishment of peace with Lithuania, and in 1570 the " Consensus Sandomiriensis " was held here for uniting the Lutherans, Calvinists and Moravian Brethren . Subsequent wars, and especially the Swedish (e.g. in 1655) ruined the town even more than did numerous conflagrations, and in the second part of the 18th century it had only about 2000 inhabitants . Here in 1702 the Polish supporters of Augustus of Saxony banded together against Charles XII. of Sweden . The beautiful cathedral was built between 1120 and 1191; it was rebuilt in stone in 1360, and is one of the oldest monuments of Polish architecture . Two of the churches are fine relics of the. t3th century .

The

castle, built by Casimir III . (14th century), still exists . The city gives title to an episcopal see (Roman Catholic) .