Sir Arthur Richards (Governor 1943–1948) promulgated the 1946 constitution to replace the Clifford Constitution of 1922. It introduced three Regional Houses of Assembly (Northern, Western, Eastern) with limited deliberative powers and a central Legislative Council in Lagos — the first time Nigerians from across the country sat in a single legislature with formal representation from the North. Crucially, the constitution was drafted in London and proclaimed without consulting Nigerian opinion.
Nnamdi Azikiwe and the NCNC mounted a national tour against the constitution in 1947, presenting petitions to the Colonial Office in London. The agitation forced its replacement within five years by the Macpherson Constitution (1951), but Richards's regional template — with all its centrifugal consequences — survived every subsequent constitutional revision and remains the foundation of modern Nigerian federalism.