In the ensuing 'Kilmainham Treaty', the government agreed to release Parnell in return for his co-operation in making the Land Act work. Forster resigned and the new Chief Secretary, Lord Frederick Cavendish, was killed by members of the Irish National Invincibles - a small radical faction of the Irish Republican Brotherhood - on 6 May 1882, leaving the 'Kilmainham Treaty' almost useless. Many, including Parnell, believed that Chamberlain, having brokered the agreement, would be offered the Chief Secretaryship, but Gladstone appointed Sir George Trevelyan instead. Nevertheless, Chamberlain maintained an interest in Irish affairs, and proposed to the Cabinet an Irish Central Board that would have legislative powers for land, education and communications. This was rejected by the Whigs in Cabinet on 9 May 1885.