In the year 1200, he led an expedition in Africa. Taking advantage of his absence, the kings of Castile and Aragon invaded Navarre, which lost the provinces of Alava, Guipuzcoa and Vizcaya to Castile.
His leadership was decisive in the Battle of Las Navas de Tolosa in the year 1212.
Sancho went into retirement ("el Encerrado") at some point, when his sister Blanca took administration of the kingdom (see note in Kings of Navarre family tree).
Sancho VI of Navarre
|List of Navarrese monarchs||
Theobald IV of Champagne