The exhibition cycle "Gallery of one painting" presents in a slightly expanded formula, two works of Venetian master Tintoretto (1560-1635): St. John the Baptist and St. John the Evangelist. The origin of both paintings was connected with the foundation of collegiate in Zamość by the chancellor and Grand Crown Hetman Jan Zamoyski. The magnate was also the author of the iconographic program of the main altar, according to which the greatest painting was to present the Resurrected Christ with St. Thomas the Apostle and paintings in the side parts of the altar: St. John the Baptist and St. John the Evangelist. In order to assure a high artistic standard to the presented works, the paintings were ordered at the renowned Venetian workshop of Domenico Robusti, called Tintoretto (1560-1635), son and a long-time collaborator of one of the greatest Renaissance painters - Jacopo Tintoretto. In the Zamość collegiate, the artwork of Domenico Tintoretto remained until 1781, when it was decided to move it, together with the entire main altar, to the church in Tarnogród, a town in the district of Zamość. During the move, the paintings with Christ and St. Thomas and God were lost. The exhibition in the Royal Castle would not have been possible if both paintings - stolen from Tarnogród in 1994, were not found six years later. The recovered artworks underwent thorough conservation, which brought out their qualities and the craftsmanship of the Venetian master.