ENIt is generally accepted in literature on the subject that the gate of the Radziwiłł castle in Biała in the Podlasie region was erected in the years 1698-1701 by the architect Andrzej Jeziornicki for Karol Stanisław Radziwiłł, the Grand Chancellor of Lithuania. A more recent hypothesis proposes, upon the date 1730 discovered on the gate, that it comes from the 1730s and was connected with Anna Radziwiłł, nee Sanguszko. An analysis of the forms of the gate faęade shows, however, that the crowning attic, decorated with Regency ornaments, is later than the remaining parts with which it does not constitute an integral whole. Archive materials which document the activity of Jeziornicki also do not provide a clear answer as regards authorship and the origin of the gate, dated ca 1700. Decisive arguments concerning the dating of the gate facade are offered by its contentual programme which distinctly stresses virtus bellica. Its elements encompass a triumphal arch, Doric order, rustication, busts of Mars and Minerva, personifications of lustitia and Fortitudo, placed below, as well as panoply configurations and individual fragments of knights’ armour and costume. The Radziwiłł coat of arms, situated over the bust of Mars, shows that one of the representatives of the family was envisaged as a god of war. This could be only Michał Kazimierz Radziwiłł (1635-1680), the voivode of Vilno, subcamerarius, the Field Hetman of Lithuania, and the brother-in-law of King Jan III Sobieski.The Prince was renowned for particular valour in the victorious battle of Chocim, waged on 11 November 1673, which was of greatest importance for the fate of the Commonwealth in the seventeenth century since it saved the country’s independence. Apparently, the programme of the entrance gate to the residence in Biała was connected with that battle; it was not only a porta triumphalis erected for the victor but also a monumentum victoriae - raised as a votive offering in return for superiority over the enemy. This assumption is supported by the spolia hostium and signa militaria in the decoration of the gate, offered ex voto Deo Optimo Maximo - the letters D.O.M. were formerly part of the facade - as well as by the compositional scheme of the whole, which referred not only to a triumphal arch but also to the portico of an ancient temple.In the light of the above findings, the time of the gate’s origin should be established as 1674-1680, and the initiative of its erection and the preparation of the programme as ca 1674-1675 (later M. K. Radziwiłł took part in other battles, and finally, went abroad where he died). Analogies with the elevation of the Wilanów palace, designed by Augustyn Locci, demonstrate a link with currents prevalent in Warsaw at that time. A. Locci was also employed in Biała by Katarzyna Radziwiłł nee Sobieska, the wife of M. K. Radziwiłł, and the sister of Jan III Sobieski. Quite possibly, the church of the Reformed Franciscans founded by her in Biała was not the sole realization of this artist. In the eighteenth century the gate was partially redesigned by the successive owners of Biała. An attic added over the crowning cornice comes from the 1730s while the decorative elements and inscriptions which were included into the programme of the gate both then and in the 1760s, and which were mentioned in eighteenth-century inventories, have not survived up to our times.