In 1539, Francisco de Ulloa under commission from the Viceroyalty of New Spain and New Spain (Mexico) conqueror, Hernán Cortés, explored the Gulf of California to the Colorado River—establishing Baja California as a peninsula. Ulloa then went south down the Baja California peninsula in the Gulf of California and rounding the tip of the peninsula turned north and explored the west coast of the Baja peninsula—perhaps to the 28th parallel (near the Isla Natividad). Ulloa's sailing ships battered by adverse winds and his men wracked by scurvy, returned to New Spain (Mexico) without exploring further.