Guido de Lavezariis (also incorrectly spelled Labazares and several other alternatives) was a merchant and banker in Mexico City from 1536 till the mid-1560s, who became a financier of and sent an agent on the Coronado Expedition. In 1542-1548 he severed as contador/accountant for the Villalobos voyage, the third phase of Mendoza's plan to complete the Columbian project. After that voyage, he asserted and others corroborated that he had a derrotero/navigation guide for a return route from the Philippines to Nueva España. Later still, he was sent to map the northern coast of the Gulf of Mexico in preparation for the Luna expedition to La Florida. Shortly thereafter, he was appointed tesorero/treasurer of the Loaysa voyage to the Philippines. When Loaysa died, Lavezariis became interim governor of the Philippines. Moving its capital to Manila, he dramatically increased trade with Chinese junks. Lavezariis was a native of Sevilla, Andalucía, Spain, the son of a Genoese father and a Spanish mother.