German spearheads broke through the Peronne–Cambrai gap and threatened Boulogne and Calais, cutting the lines of communication of the Allied armies of 1 (General Gaston Billotte) in the North-East Theatre of Operations ( Alphonse Joseph Georges), separating them from the main French armies south of the Somme. On 19 May, General Edmund Ironside, the British Chief of the Imperial General Staff, conferred with Lord Gort, commander of the BEF, at his headquarters near Lens and urged Gort to save the BEF, by attacking towards Amiens to the south-west but Gort had only two divisions available for an attack. Ironside met Billotte, finding him apparently incapable of taking action. Ironside returned to Britain and ordered urgent anti-invasion measures.