Azcue, Fernando De
AZCUÉ, FERNANDO DE (?–?). Fernando de Azcué, alcalde mayor of Saltillo, is credited with the first definite crossing of the Rio Grande by a European. In 1665, in response to continuing Indian attacks, Azcué recruited a company of 103 men from Saltillo and Monterrey.
Full article on the Texas State Historical Association's Handbook of Texas Online