 In late September 1521, the Franco-Navarrese divided in two columns and advanced towards the Bidasoa.The first column, made up of Agramont-party Navarrese, Normans, and Gascons, was based in Labourd (in French royal territory), while the second, formed by German, Gascon, and Norman infantry, set off from Saint-Jean-Pied-de-Port—then in the hands of troops loyal to Henry II.A total of 27,000 combatants were under the command of Guillaume Gouffier, seigneur de Bonnivet.