The Fifth Regiment, Spanish: Quinto Regimiento (full name Quinto Regimiento de Milicias Poulares), was an elite corps loyal to the Spanish Republic at the onset of the Spanish Civil War. Made up of volunteers, the Fifth Regiment was active in the first critical phase of the war and became one of the most renowned units loyal to the Republic.The number of soldiers in the Fifth Regiment quickly rose from about 6,000 in August to over 20,000 in November 1936.