In 1512, Navarre was invaded by a combined Castilian-Aragonese army sent by Ferdinand II of Aragon, whose second wife was Germaine de Foix (1490–1538), a cousin of Queen Catherine. The Castilian troops commanded by the duke of Alba crossed the Pyrénées onto Lower Navarre capturing St-Jean-Pied-de-Port on 10 September 1512 and wreaking havoc across much of the "merindad". There the Castilians were doggedly opposed by lords loyal to John III and Catherine of Navarre, but the Castilians retained St-Jean-Pied-de-Port and its hinterland. Following the invasion, Navarre south of the Pyrenees was annexed to Castile nominally as an autonomous kingdom ("aeque principalis") by the victorious Ferdinand after taking an oath to respect (1515).