Gaspar Castaño de Sosa

1595, Molucca) was a Portuguese settler, colonist, explorer, and reputed slaver who was among the founders of the towns of Saltillo and Monclova, in Coahuila, Mexico.

[1] He led an expedition, deemed illegal by Spanish authorities, and attempted unsuccessfully to establish a colony in New Mexico in 1590 and 1591.

[3] Castaño appears in the history of northern Mexico about 1579 when along with Luis de Carabajal y Cueva he was one of the early settlers in what became the Mexican state of Nuevo León.

[10] In the bitter cold January 1591, Castaño and his men prospected the area unsuccessfully for deposits of precious minerals.

[11] Members of the expedition then visited various towns up and down the Rio Grande river valley and explored the nearby mountains for silver.

The pueblos had been visited by two expeditions during the preceding decade, Chamuscado and Rodriguez and Antonio de Espejo, so they were familiar with Spaniards.

[12] Along this retreat, two of Castaño's captured Keresan interpreters, Tomas and Cristobal, were abandoned at Santo Domingo pueblo; they were later re-encountered by Juan de Oñate's official expedition in the summer of 1598.

The Viceroy in Mexico City ordered Captain Juan Morlette to gather 40 soldiers and a priest and go in pursuit of Castaño to arrest him, by force if necessary.

[14][2] On March 5, 1593, Castaño de Sosa was convicted of invasion of lands inhabited by peaceful Natives, raising troops, and entry into the province of New Mexico.

He was sentenced to six years of exile in the Philippines and performing such duties as might be required by the Governor there under penalty of death if he defaulted from his service.

[2] The order of the reversal arrived too late for him, however, as he had been killed in the Molucca Islands when Chinese slaves aboard his ship mutinied.