The polyptych for the altar of St Martin in the Zadar Cathedral, commissioned from Vittore Carpaccio by Canon Martin Mladošić, is one of those works from the painter’s oeuvre whose chronology is still not agreed upon. Various authors dated the Zadar polyptych to almost the entire range of the painter’s activities, from those who considered it a youthful work to those who considered it a late work, created at the very end of his career. The document that was recently found in the Zadar archive sheds a completely new light on the issue of dating the polyptych, excluding all dating in the early years of Carpaccioʼs work, but at the same time exposes the conditions and circumstances of its commission and creation. Namely, on September 12, 1497, in Zadar, Martin Mladošić appointed two representatives, who were supposed to demand from the painter Victor Scarpation (Vittore Carpaccio) in Venice to complete the work on the altarpiece for the altar of St Martin in the cathedral of St Anastasia in Zadar, in accordance with the contract he had previously concluded with the client. It was stated that, if the painter failed to do this, they should take from him the frame carved in Zadar and order the painting from other masters at his expense. However, if he completed and submitted the work, they should cancel the previously concluded contract. Considering Carpaccioʼs signature on the painting, it is obvious that the latter was ultimately achieved. And in the light of the fact that the client and the painter met in person, it can be assumed that the depiction of the donor in the painting is indeed a realistic portrait of a prominent Zadar canon. In combination with the previously known information from Mladošićʼs will, dated April 21, 1496, which referred to the making of the frame, it can be established that the polyptych was commissioned in 1496, and that the painting lasted until the end of 1497 or the beginning of 1498. Dated in this way, the Zadar polyptych can be precisely placed in the time between the two great Carpaccioʼs cycles, that is, after the completion of the Cycle of St Ursula and before starting work on the cycle at the Scuola di San Giorgio degli Schiavoni. The life of Martin Mladošić, in addition to his own notarial books, is witnessed by numerous archival documents, from which it is possible to partially reconstruct his biography, especially his career progression and position within Zadarʼs ecclesiastical circles, where he stood out as one of the most important and influential members of the cathedral chapter. Despite certain disagreements between the chapter and the archbishop, he remained the closest associate and confidant of Archbishop Maffeo Vallaresso. After Vallaressoʼs death, during the vacant episcopal seat, he seems to have been the head of the Zadar church hierarchy, and he retained a key role during the episcopate of Giovanni Robobello. The rise of his ecclesiastical career was accompanied by material prosperity, a luxurious house in the city, and extensive land holdings. So, investing in his own altar in the cathedral was a logical reflection of Mladošićʼs well-being and position. Also, we can assume that Mladošić, satisfied with Carpaccioʼs work, and still connected with the Vallaresso family, played a certain role in his engagement for the work in Scuola di San Giorgio degli Schiavoni.