The Committee's membership was drawn from members of both the House of Lords and House of Commons, and also included Scottish representatives and other influential persons. During 1644 and 1645 its members were:
Attendance in 1644 was patchy, since before the enactment of the Self-denying Ordinance, many of the members of the Committee had commands in the field. (Warwick was the Lord High Admiral).
The Committee had to accommodate several factions within its own ranks. It was also subject to the control by Parliament (though the need to pass legislation or resolutions through both Houses meant that the Committee could control matters on a day-to-day basis without much interference).
Its greatest achievement was the establishment of the New Model Army, and the maintenance of this army and other forces in the field until King Charles was defeated in 1646. The Committee provided a continuity of policy and administration which the King could not match.