It was first mentioned in 1414 as a fortress protecting Pskov from the south, when Vytautas of Lithuania sacked it. Prince Ivan Shuysky built a wooden fortress there in 1535. In the 16th century, the fortress defended the Western approaches to the Grand Duchy of Moscow. The Poles captured it during the Livonian War and held until the First Partition of Poland. The fortifications of Sebezh, now dismantled, were reinforced at the behest of Peter the Great during the Great Northern War. The castle hill is still dominated by the Roman Catholic Church, built in 1625-1648 and reconsecrated as a Russian Orthodox Church in 1989.