In a matter of months, the Tanzania People's Defence Force (TPDF) and its Ugandan rebel allies (unified under the umbrella organisation, Uganda National Liberation Front (UNLF)) defeated the Uganda Army in a number of battles, and occupied Kampala, Uganda's capital, on 11 April 1979. With his military disintegrating, Amin's rule collapsed. Having escaped from Kampala, he traveled to a succession of cities in eastern and northern Uganda, urging his remaining forces "to go back and fight the enemy who had invaded our country", even as he prepared to flee into exile. Most Uganda Army units opted to surrender, desert or defect to the Tanzanian-led forces, but some decided to continue to fight for Amin's defunct regime. The Tanzanians and the UNLF allies continued their advance to secure eastern and northern Uganda.