5 November 1965
On 5 November 1965 Rhodesian( now Zimbabwe) Prime Minister,Ian Douglas Smith, declared a state of emergency. This was prompted by the United Kingdom’s (UK) refusal to grant Zimbabwe independence after Tanganyika and Northern Rhodesia (now known as Zambia) and Malawi. The British government refused to yield to their demands without amendments to the colony's constitution, including a graduated extension of the franchise leading to eventual African rule. On 11 November, the Smith government issued a unilateral declaration of independence (UDI). The British government viewed UDI as illegal and imposed limited economic sanctions.  These measures did not bring about the desired results.
References

Boddy-Evans A. ‘This day in African history:05 November’, from About African History, [online], available at www.africanhistory.about.com (Accessed: 27 September 2012)|

Encyclopedia of the Nations, ‘Zimbabwe-History’, [online], available at www.nationsencyclopedia.com (Accessed: 27 September 2012)|

Institute of Commonwealth Studies, ‘Rhodesia UDI 1965 - Online Exhibition’, [online], available at https://commonwealth.sas.ac.uk (Accessed: 27 September 2012)