Abstract
The objective of this article is to study the military career of Gabino Gaínza y Fernández de Medrano, a Spanish military and politician born in Pamplona, Navarra, who became the first Political Chief of the former independent General Captaincy of Guatemala. For its realization, the documentation of the sources available on his life and military career in the main Spanish archives has been studied, and very especially in the General Archive of Simancas, the General Archive of the Indies, and the National Historical Archive, as well as the process that was followed in Valparaíso in 1815 because the signing of the Treaty of Lircay, and the main bibliographical references that deal with his person and time.