The Treaty was approved by the British Parliament soon after, followed by the Irish Dáil in early 1922. In March 1922 Michael Collins and James Craig signed the "Craig–Collins Agreement", an attempt by them to deal with the boundary question without recourse to the British government. Despite Article 12 of the Treaty, this agreement envisaged a two-party conference between the Northern Ireland government and the Provisional Government of Southern Ireland to establish: "(7) a. Whether means can be devised to secure the unity of Ireland" and "b. Failing this, whether agreement can be arrived at on the boundary question otherwise than by recourse to the Boundary Commission outlined in Article 12 of the Treaty". However, this agreement quickly broke down for reasons other than the boundary question, and Michael Collins was later killed by anti-Treaty elements. The Irish Free State government thus established the North-Eastern Boundary Bureau (NEEB), a government office which by 1925 had prepared 56 boxes of files to argue its case for areas of Northern Ireland to be transferred to the Free State.