It was not the first use of the name "Guzman el Bueno" for an army division: Division de Infanteria Experimental No. 21 "Guzman el Bueno" (DIE 21) had existed from the 1950s as part of the Spanish "Pentomic" structure. The previous DIE 21 had been part of Army Corps 2 (Seville) and had had its headquarters at Algeciras, including "Agrupación de infantería" (AIs) at Sevilla (AI "Soria" 9); AI "Extremadura" 15 (Algeciras); AI Pavía 19 (San Roque); AI Álava 22 (Tarifa); and AI "Granada" 34 (Huelva), plus "Agrupación Blindada Sagunto No. 7" (Cavalry Group No. 7 "Sagunto", located at Seville); RACA 14 at Seville; and battalions of sappers and signallers at Cadiz.