In 1544 Valdivia commissioned Captain Juan Bautista Pastene to explore the coast from Valparaiso to the Strait of Magellan,[1] and installed his personal secretary Juan de Cárdenas in the expedition to produce a written account of the lands discovered in order to solidify his claims before the King.[18] Although Pastene's expedition reached only the 41st parallel south, well short of the strait, it discovered San Pedro Bay and the mouth of Valdivia River, where Valdivia would later found the city that bears his name.[19][20] As Valdivia consolidated his claims, he mentions in a 1548 letter to the Council of the Indies the possibility of establishing contacts between Chile and Seville through the strait.[18]