Trotsky once again offered an alliance, sending a plenipotentiary delegation from the Central Committee of the Bolshevik Communist Party, headed by Comrade Ivanov to propose a military and political treaty of alliance; Makhno agreed, subject to a pardon of all Anarchist prisoners throughout Russia. The treaty was drawn up and signed on October 15, 1920 at Starobel'sk by anarchist military and political representatives and the Bolshevik Communist delegation. The treaty, along with a Makhnovist delegation then traveled to the Bolshevik-held city of Kharkiv for official ratification and to plan a common military strategy. Using the arms and munitions previously captured from General Wrangel's infantry brigades in southern Ukraine, Makhno and the Black Army went on to clear much of Crimea of Cossack cavalry, and helped force a retreat of Wrangel's remaining infantry brigades. After an unsuccessful northern offensive against the Red Army, Wrangel and the last of his forces were evacuated from Sevastopol by the White and French Navy on November 14, 1920.