The baroque "palazzo in fortezza" in Łańcut underwent its first radical alterations in the late 18th and early 19th centuries. Its owners at the time were Duke Stanisław Lubomirski (1722–1782) and his wife Izabela "née" Czartoryska. Initial transformations were conducted by the Lubomirskis together and after her husband's death in 1783, the Duchess continued the work by herself. She also began to expand the complex and, being a great admirer of baroque architecture, continued to transform the castle into a palace.