'Casus belli'. Ivan the Third’s Declaration of War to Aleksander Jagiellończyk, June 24th, 1500

The paper presents a missive from the Grand Duke of Moscow Ivan III declaring war to the Grand Duke of Lithuania Aleksander Jagiellończyk on June the 24th, 1500. The missive, so far unaccounted in scientific publications, survives in a Middle Low German translation kept in the archive of the Hanseatic City of Lübeck. The declaration of war is motivated by alleged injustices done to Ivan III, to his subjects and to his daughter Elena Ivanovna, who was Aleksander’s wife. Judging by the particular dialect of Low German, the translation was made in Lübeck. Its literality allows conclusions about the content of the original missive and the sources on which it was based. Analysis shows that the arguments included complaints formulated by Muscovite diplomats after the conclusion of the ‘eternal peace’ of 1494, beginning with the negotiations in 1495. Compared to indirect and short textual evidence available so far, this document gives a fuller picture of the events, including a more precise date of the beginning of the Muscovite-Lithuanian War of 1500–1503: brought together, all sources show that the declaration was made by Ivan III with considerable delay, months after warfare had begun. The document also demonstrates how the 15th-century Russian state used official documentation in its foreign policy and which role the emerging bureaucratic class played in it. The published document is accompanied by a Russian translation.