Operation Reconquest of Spain Historical milestone · Bossòst, Val d'Aran, Lleida Image of Bossòst, not of the place itself. On 19 October 1944 several thousand guerrillas of the Agrupación de Guerrilleros Españoles crossed the border and occupied for days towns of the valley, waiting for a general rising. The army expelled them in little more than a week. 1944 Photo: Isidre blanc (CC BY-SA 4.0) What to see and do in Bossòst