Major General Rezaqul Haider was commissioned in Pakistan Army in the 34 Frontier Force Regiment. After repatriation from Pakistan in 1974 he served in Bangladesh Army in various appointments. He possessed vast command, staff and instructional experience. As Brigadier General, he was selected in UN assignment as the Chief Military Liaison Officer in UNAMET and later as Chief Military Observer in UNTAET in East Timor. Thereby he was witness to the struggle for Independence of East Timor from Indonesia. He retired from active duties of the Army in 2006. He was Director General of Bangladesh Rifles, now Border Guard Bangladesh in 2001. He was also the Bangladesh Ambassador to Turkey before retirement.