Siemiginowski was of Armenian origin. He was born in Lwów in the Polish–Lithuanian Commonwealth and was the son of a painter Jerzy Szymonowicz and Teodozja née Korunka. In 1677 he was entrusted to the kingJohn III Sobieski by his parents and was sent by the king to Rome. Before he went to Rome he probably spent at least a year, possibly two, in Paris. In 1682 due to recommendation of king John III he was admitted to Accademia di San Luca in Rome, he receive the Knighthood of the Golden Spur and the title of Eques Auratus from the Pope Innocent XI. On 11 January 1682 he also took first place award in the Academy's contest for two of his drawings Construction of the Tower of Babel, and God's anger caused by the building of a tower and was protected by the Pope's nephew Livio Odescalchi. In Rome he was trained by Lazzaro Baldi, Luigi Garzi and Carlo Maratta. Shortly after his return to Poland in 1684 he was ennobled by the king and took the name of ChevalierEleuter. In 1687 John III granted him the village Łuka near Złoczów to confirm his nobility. After king's death he became secretary of Augustus II the Strong and was a court painter of Aleksander Benedykt Sobieski. At that time he still worked in Wilanów and supervised the construction of new palace's wings. In 1701 he was adopted by the impoverished noble family of Siemiginowski and since that time he used their name. Siemiginowski was married four times and had 11 children. In 1704 he had a house in Warsaw and a manor house at Wielopole near Warsaw. He died probably between February 28, 1708 and March 13, 1711. Siemiginowski-Eleuter was the main artist who was responsible for decorating and painting of the interior of Wilanów Palace in Warsaw. His painting was heavily influenced by French artists of the Baroque. Similarities with plafonds by Charles Le Brun in his works making his visit in Paris more probable. Influences of Carlo Maratta and Nicolas Poussin are also visible in his works. He painted antiquitised portraits of the members of the royal family and made engravings in participation of Charles de La Haye. Siemiginowski painted many frescoes, notable for their many colors. His subject matter varied between dramatic scenes to peaceful landscapes. Among the most notable of his works are four plafonds of the four seasons in the Wilanów Palace. Siemiginowski established his own school of painting in Wilanów and was a renowned architect. Many of his religious paintings in Warsaw were destroyed during the extensive bombardment of the city by the Germans in 1944.
