Secemin prospered in the period known as the Polish Golden Age. The decline of the town began during the catastrophic Swedish invasion of Poland (1650s), when it lost most of the population, which was replaced by Jewish settlers. Secemin remained in the hands of the Szafraniec family until the mid-17th century, when, as a dowry, it was transferred to Jan Samuel Czarnocki (Lis coat of arms), the husband of Zofia Szafraniec. The Czarnockis owned the town until 1788, building here a manor house, which was demolished in the 1970s.