Louis prospered initially due to much of the civil strife following the War of the Bands in the Basque territories of Castile and Navarre, present-day northern Spain.
In a treaty between the Navarrese monarchs and King Ferdinand II, Ferdinand promised to stop warring on Navarre or Béarn, Louis would hand over some strategic fortresses in exchange for new lands in Granada.
However, when Louis refused to surrender the castle of Viana in 1506, the crown decided to crush the rebellious count for ever, restoring royal authority and patrimony.
The castle was held by Louis de Beaumont and Cesare was killed during the battle.
[1] In 1507 Louis was charged with treason, dispossessed and sentenced to death, but he escaped to Aragon where he died in 1508 at Aranda.