17 January 1525,
They began the witch hunt in the valleys of Erro, Roncal and Salazar. Driven by Pedro de Balance, member of the Spanish Royal Council, under the excuse of superstition and religious fanaticism, more than 200 people were arrested, mostly women, and hanged in dozens. All were citizens who stood against the conquest of Castile. Besides causing scandal, they caused a lot of fear. The presbyters of the villages and the Courts of Navarra complained that the persecution was based on false cases and torture.
Source:
Joseba Asiron and Martín Altzueta, 50 key dates of the conquest of Navarra (1512-1525) (Txalaparta).