 The Nationalist attack started with the Navarrese Division, led by the General José Solchaga.This division had four brigades led by the Colonels Garcia Valiño, Alonso Vega, Cayuela and Latorre (18,000 men) and the Black Arrow division (8,000 men with Italian officers).This force was established between Vergara and Villareal, on the border of the Biscay province.