Terence MacSwiney was a founding member of the Cork Brigade of the Irish Volunteers. Like the other leaders, his dedication was enormous, and he would cycle early in the morning on his bike to remote parts of West Cork to drill the men. He was also a crucial player in the plot to meet the Aud at Fenit pier, where the German navy were supposed to deliver 40,000 guns to arm the Irish rebels.
During the Easter Rising, Terence MacSwiney was second in command to Tomás MacCurtain, Commander of the Cork Brigade of the Irish Volunteers. Over 1000 troops mobilised in Cork on Easter Sunday, but like other frustrated leaders around the country, he stood down his troops on the countermand of Eoin MacNeill, when MacNeill heard that Casement had failed to land the German guns.