Union of Krewo

14 August 1385, at Kreva Castle

At Kreva Castle on 14 August 1385 — the Monday before the Feast of the Assumption, as the act itself dates it — Grand Duke Jogaila issued a Latin document ratifying terms his envoys had negotiated with representatives of Queen Elizabeth of Bosnia and Polish lords. The subject was his proposed marriage to Jadwiga and his accession to the Polish throne.

The surviving parchment runs 26 lines, roughly 560 words. It is small, hastily prepared and visibly corrected.

What Jogaila actually promised

Roman-rite baptism for himself, his unbaptised relatives, nobles and people. The release of all Christian captives, efforts to recover lost lands, and payment of the 200,000 florins specified under Jadwiga's earlier marriage arrangement with William of Austria.

And the perpetual applicare of his Lithuanian and Ruthenian lands to the Polish Crown — a verb with no single uncontested legal reading, proposed translations running from incorporation to a looser dynastic association.

His brothers Skirgaila, Kaributas and Lengvenis and his cousin Vytautas were named with him and attached their seals; those seals survived for centuries and disappeared during the nineteenth century.

None of it was executed that day

The document did not baptise Jogaila, marry the couple, crown him, convert Lithuania or create a functioning common government. Those steps remained to be carried out in 1386 and 1387, beginning with the Polish counter-pledge issued at Vawkavysk on 11 January 1386.

Scholars agree the parchment is authentic and dispute what it legally is. One major Lithuanian diplomatic study classifies it as a ratification or authenticated protocol of marriage negotiations rather than an interstate treaty constituting a union.

The Jagiellonian dynasty was not established on 14 August: Jogaila had not yet been baptised, married or crowned.