 Republican counterattacks along the captured ground likewise failed, resulting in heavy casualties to both sides.By winter of 1936–37 the Nationalist forces, led by General Francisco Franco, having failed to carry Madrid by storm in November 1936, resolved to cut off the city by crossing the Jarama to the south east and severing Madrid's communications with the "pro tempore" Republican capital of Valencia.General Emilio Mola was in overall command of the Nationalist forces around Madrid and planned an offensive across the Jarama south of the capital.