The 1966 Military Coups and Their Impact on Nigerian Constitutional Development

This study examines the January and July 1966 military coups in Nigeria and their transformative impact on the country's constitutional development trajectory from 1966 to the present. The coups ended Nigeria's First Republic and established a pattern of military intervention in politics that would dominate Nigerian governance for much of the subsequent three decades, leaving a constitutional legacy of centralisation, weakened federalism, and eroded civil liberties. Using a descriptive historical design, the study reviews military decrees, constitutional amendment records, government white papers, and secondary academic literature published between 2020 and 2024. The Civil-Military Relations Theory and the State Formation Framework provide the analytical lenses. Findings reveal that the military era fundamentally restructured Nigerian federalism, increasing the power of the federal centre at the expense of state and local governments through the proliferation of federal exclusive legislative items, the concentration of oil revenue control, and the suppression of independent state judiciaries. The study identifies revenue allocation centralisation, land use legislation, and the elimination of elected local governments as the most enduring constitutional distortions introduced during military rule. Keywords: 1966 military coups, Nigerian constitution, military rule, federalism, constitutional development.