Then held by the Vítkovci Neuhaus (Hradec) family, the estates were given in pawn to the House of Rosenberg by King John of Bohemia in 1337.
[3] In 1475, the noble Lobkowicz family took over Sedlčany in exchange for Rožmberk Castle, given in pawn by the Bohemian chamberlain John II of Rosenberg in 1464.
Upon his death in 1604 the last Rosenberg scion Peter Vok sold Sedlčany to the Bohemian chancellor Zdeněk Vojtěch Popel of Lobkowicz, who administered stern Counter-Reformation measures to its citizens.
The town was devastated by Swedish troops during the Thirty Years' War and did not recover until the mid 18th century.
Until 1918, Sedlčany was part of Austria-Hungary and was the administrative seat of a district of the same name, one of the 94 Bezirkshauptmannschaften in Bohemia.
[4] Sedlčany developed to a centre of textile industry, the local economy was further promoted when the town received access to the railway line to Olbramovice in 1894.
Under the Protectorate of Bohemia and Moravia the nearby SS-Truppenübungsplatz Böhmen was laid out from 1941, whereby numerous villages were cleared and the inhabitants expelled.
[8] The main landmark of Sedlčany and the oldest building is the Church of Saint Martin.