On 1 April 1656, in the besieged city of Lwów, King John II Casimir Vasa stood before the altar of the cathedral and swore a solemn oath that would echo through Polish history: he entrusted the Polish-Lithuanian Commonwealth to the protection of the Virgin Mary, declaring her the Queen of Poland. This act, known as the Lwów Oath, came at the darkest hour of the Swedish invasion—the “Deluge”—when the nation’s fate hung in the balance. Jan Matejko’s 1 April 1656 Oath by John II Casimir Vasa seizes this turning point, a moment that has inspired both patriotic fervor and centuries of debate over its true impact. Matejko captures the king mid-vow, his hand raised, eyes lifted not to the assembled nobles but to the heavens, as if seeking direct communion with the divine.

The bishop beside him holds the Gospel, anchoring the act in both faith and law, while the anxious faces of senators and soldiers crowd the foreground, their postures tense with hope and desperation. The artist’s use of light isolates the king and altar, casting the surrounding figures into a shadowed uncertainty, underscoring the nation’s peril. This dramatic focus recalls the theatricality of Delacroix’s Liberty Leading the People, though Matejko’s vision is less about revolution and more about sacred intercession and national destiny. Painted in 1893, late in Matejko’s career, this work exemplifies his devotion to monumental Polish history painting—a genre he shaped more than any other artist of the 19th century.

The exact medium is not always listed, but his large canvases typically employed oil on canvas. Like many of his major works, the painting was likely intended for public display, to inspire and educate in an era when Poland’s sovereignty was still denied by partitioning powers. Today, 1 April 1656 Oath by John II Casimir Vasa is held in a Polish national collection, continuing to serve as a touchstone for debates about faith, patriotism, and the uses of history in art.