Church founders: Steponas Pacas, Kristupas Zigmantas Pacas (1621–1684), Antanas Pacas (1722–1774), Teresė Radvilaitė-Pacienė (?–1780); in 1929, the restorer of the frescoes is the artist Vytautas Bičiūnas (1893–1945). In 1633, after purchasing the Jieznas manor, Steponas Pacas, the treasurer of the Grand Duchy of Lithuania, started the construction of the palace and the church. In 1640, the construction of the church, following his father's will, was continued by his son, a chancellor of the Grand Duchy of Lithuania, Kristupas Zigmantas Pacas. In 1670, Bishop Kazimieras Pacas of Lower Lithuania (Samogitia/Žemaitija) consecrated the Church with the name of Saint Archangel Michael and John the Baptist. The exterior and interior decoration of the church is in the Baroque style. Inside the church there are many frescoes, the interior is decorated with an ensemble of twelve altars. The main altar is decorated with a large picture of the Saint Archangel Michael (the original’s author and artist is Gvido Remi, the original is kept in the Capuchin Monastery in Rome, a copy was made by N. Silvanavičius in 1875). The chapel in the basement has an altar with a wooden statue of Christ. This sculpture is considered to be miraculous.