Vivente Rege is a form of king's election, where the king's successor, usually of the same dynasty

Dynasty

A dynasty is a sequence of rulers considered members of the same family. Historians traditionally consider many sovereign states' history within a framework of successive dynasties, e.g., China, Ancient Egypt and the Persian Empire...

, was elected before the old king died. It was an important element of politics in Poland

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

 during the times of the nobilities' election of kings, when monarchs would attempt to push through the election of their heir, and Polish nobility (szlachta

Szlachta

The szlachta was a legally privileged noble class with origins in the Kingdom of Poland. It gained considerable institutional privileges during the 1333-1370 reign of Casimir the Great. In 1413, following a series of tentative personal unions between the Grand Duchy of Lithuania and the Kingdom of...

) would oppose it, on the grounds that it would lead to absolute monarchy

Absolute monarchy

Absolute monarchy is a monarchical form of government in which the monarch exercises ultimate governing authority as head of state and head of government, his or her power not being limited by a constitution or by the law. An absolute monarch thus wields unrestricted political power over the...

.