10 June 1966
In June 1966, Ugandan Prime Minister, Milton Obote announced the proposed division of the province of Buganda into four districts. Ruled by the powerful Kabaka or king installed by the departing British Colonial government, Buganda was the most powerful province independent Uganda and considered a threat to the central government Hence the decision to divide the province into four districts. The division took effect in 1967and the Kabaka’s government was dissolved. Prior to the adoption of the 1967 constitution, local government administration functions in Buganda were performed  by six ministers advised by the Buganda council and by a hierarchy of chiefs. The move by Obote took place five years after Uganda gained independence from Britain in 1962 with Obote as the first Prime Minister.
References

Answers.com, ‘Buganda’, [online], available at www.answers.com(Accessed: 15 May 2012)|Boddy-Evans A. ‘This Day in African History: 10 June’, from About African History, [online], available at www.africanhistory.about.com(Accessed: 15 May 2012)