Pacta conventa (Latin for "agreed-upon undertakings") was a contractual agreement, from 1573 to 1764 entered into between the "Polish nation" (i.e., the szlachta (nobility) of the Polish-Lithuanian Commonwealth) and a newly-elected king upon his "free election" (wolna elekcja) to the throne.[1]
The pacta conventa affirmed the king-elect's pledge to respect the laws of the Commonwealth and specified his undertakings and promises in such realms as foreign affairs, taxes, public debt, the military, etc. The document was drawn up by the election sejm (sejm elekcyjny), and its acceptance by the king-elect was a condition of his elevation to the throne.
An example of the various concrete undertakings found in a king-elect's pacta conventa is King Władysław IV Vasa's pledge to create a Polish-Lithuanian Commonwealth Navy for the Baltic Sea.
In addition to his own unique pacta conventa, each king-elect was required to sign the Henrician Articles.
The distinction between the two documents gradually faded away over successive elections.