The Infantry Regiment "Asturias" No. 31 (Spanish: "Regimiento de Infantería "Asturias" nº 31") is a mechanized infantry unit in the Spanish Army. It was created in the Kingdom of Asturias on 6 July 1703. Its first commander was Álvaro Navia Osorio y Vigil, Viscount of Puerto de Vega and Marquis de Santa Cruz de Marcenado. The regiment initially consisted of 600 men. It was also known as "El Cangrejo" ("The Crab"), a name which it obtained following the campaign in Roussillon from 1793 to 1795, during which it never retreated. The patron saint of the regiment is Our Lady of Covadonga.