The trial of the Basque witches at Logroño, near Navarre, in northern Spain, which began in January 1609, against the background of similar persecutions conducted in Labourd by Pierre de Lancre, was almost certainly the biggest single event of its kind in history. By the end some 7,000 cases had been examined by by the Spanish Inquisition.
Among the accused were not only women (although they predominated), but also children and men, including priests guilty of healing with nóminas, amulets with names of saints. The first phase ended in 1610, with a declaration of auto de fé against thirty-one of the accused, twelve or eleven of whom were burned to death (five of them symbolically, as they had died before auto da fé).
Thereafter proceedings were suspended until the inquisitors had a chance to gather further evidence, on what they believed to be a widespread witch cult in the Basque region. Alonso Salazar Frias, the junior inquisitor and a lawyer by training, was delegated to examine the matter at length. Armed with an Edict of Grace, promising pardon to all those who voluntarily reported themselves and denounced their accomplices, he traveled across the countryside during the year 1611, mainly in the vicinity of Zugarramurdi, near the French border, where a cave and a water stream (Olabidea or Infernuko erreka, "Hell’s stream") were said to be the meeting place of the witches.
As was usual in cases of this kind, denunciations flowed in. Frías finally returned to Logroño with "confessions" from close on 2,000 people, 1,384 of whom were children between the ages of seven and fourteen, implicating a further 5,000 named individuals. Most of 1,802 people witnesses retracted their statements before Salazar, attributing their confessions to torture. The evidence gathered covered 11,000 pages in all. Only six people out of 1,802 maintained their confessions and claimed to have returned to sabbaths.