Muro, La expedición Legazpí-Urdaneta a las Filipinas [p.46-47: a Rodrigo de Isla was the brother of capitán Juan de la Isla, who was an important part of the administration of the armada; 101, a Rodrigo de la Isla was one of the pilots (of the patache San Juan); his brother served as captain of the same vessel; 101, Rodrigo de Isla, brother of Juan de la Isla, was pilot of the San Juan during the voyage, while his brother was captain; This information comes from Colección de Documentos Inéditos…Ultramar, Segunda Serie, Tomo 2, 374] [probably not a pilot]
Surname
Ysla