1. Hamza al-Mustapha enrolled at the Nigerian Defence Academy in Kaduna and was commissioned into the Nigerian Army in 1983.

1. Hamza al-Mustapha enrolled at the Nigerian Defence Academy in Kaduna and was commissioned into the Nigerian Army in 1983.
Hamza al-Mustapha held various command posts in the Ministry of Internal Affairs, Security Group of the Directorate of Military Intelligence, 82 Division and Army Headquarters; Ministry of Defence and The Presidency.
Hamza al-Mustapha was involved in counter-intelligence activities and at least two investigations of coup attempts; which brought him to the attention of General Sani Abacha.
Hamza al-Mustapha conducted operations in Chad, Liberia, Bakassi, Gambia and Sierra Leone.
General Sani Abacha died on 8 June 1998, following his death Hamza al-Mustapha assembled the military hierarchy in order to avoid a succession crisis.
General Abdulsalam Abubakar emerged as head of state on 9 June 1998 and Hamza al-Mustapha was removed from office and subsequently arrested.
Hamza al-Mustapha was in chains and solitary confinement for over a year, allowed only a cup of water daily and subject to psychological torture.
In May 2011, there were rumours that Hamza al-Mustapha had been murdered at the Kirikiri Maximum Security Prisons where he was being held, but these turned out to be untrue.
However, Hamza al-Mustapha was still not cleared of the alleged murder of Kudirat Abiola.
Hamza al-Mustapha ran again in 2023 under Action Alliance, but was legally disqualified after a dispute over whether his primary win over Samson Odupitan was legitimate.