The 223rd Mixed Brigade was then transferred to the Battle of Valsequillo, where on 7 January it attacked the Cerro Mulva and the Sierra de los Santos in protracted combats that lasted about week. In February it returned to its garrison in Cartagena where it took again the Coastal Defence duty. In March 1939, during Segismundo Casado's coup against Prime Minister Juan Negrín the 223rd Mixed Brigade stood against the coup, following which its commander was deposed and Militia Major Ángel Muñoz took the command. Shortly thereafter the Republican Armed Forces surrendered and the unit was disbanded.