Free election (Polish: wolna elekcja) was the election of individual kings, rather than of dynasties, to the Polish throne between 1572 and 1791, when "free election" was abolished by the May 3rd Constitution (1791).
Actually the first documented election of a Polish king had occurred in 1386, with the selection of Wladyslaw Jagiello, grand duke of Lithuania, to be the first king of Poland's second dynasty. However, while the principle of election continued in effect throughout the nearly two centuries of the Jagiellon dynasty, it actually amounted to mere confirmation of the incoming dynast.
In 1572 Poland's Jagiellon dynasty became extinct upon the death, without a successor, of King Zygmunt II August. During the ensuing interregnum, anxiety for the safety of the Commonwealth eventually led to agreements among the political classes that, pending election of a new king, supreme authority would be exercised by the Roman Catholic primate, acting as interrex (from the Latin); that confederations (Polish: konfederacje) of nobility would assume power in the country's respective regions; and that, by the "Warsaw Confederation" of 1573, peace would be maintained among the realm's various religions. The most important decision, however, was that the next king would be chosen by election, whose terms were finally established at a convocation sejm (sejm konwokacyjny) in 1573. On the initiative of southern-Polish nobles, supported by the future Crown (i.e., Polish) great chancellor and hetman Jan Zamoyski, the election would be by all male szlachta (nobles) who assembled for the purpose.
The nobles voted by province (voivodship) in the presence of deputies, who conveyed the votes to the senate: the choice of king was announced by the senate's marshal and solemnized by the primate.
Royal elections were held at Wielka Wola, outside Warsaw (now that city's western, Wola district). The stormiest elections were those of 1575 and 1587, when matters came to blows among the divided nobles. Following an election, the king-elect was obliged to sign pacta conventa (Latin: "agreed-upon agreements")--laundry lists of campaign promises, seldom fulfilled--with his noble electors. The agreements included "King Henry's Articles" (artykuly henrykowskie), first imposed on Prince Henri de Valois (in Polish, Henryk Walezy) at the outset of his brief reign (upon the death of his brother, French King Charles IX, Henri de Valois fled Poland by night to claim the French throne).
The last of the Jagiellon kings, Zygmunt August, had in 1529 been elected vivente rege (Latin: "during the [previous] king's life"); and about 1660 Queen Ludwika Maria attempted to engineer a similar election. Such elections were meant to enhance the continuity of royal power.
Beginning in 1697, Polish royal elections ceased to be truly "free" and took place under duress from foreign armies.
The largest number of participating nobles (40-50,000) attended the first free election, in 1573. The second such election, in 1575, drew only 12,000.
Free elections weakened the kings' authority, occasioned quarrels among the voting provinces (voivodships) over the candidates for the throne, and encouraged foreign dynasties' meddling in Polish internal politics. Abolition of free elections became one of the major reforms instituted by Poland's "Great" or "Four-Year Sejm" (1788-1792) in its Constitution of May 3rd, 1791.
Prior to the abolition of "free elections," 13 were held in Poland, resulting in the elevation of the following kings: