In 2013, general Theodoru took control over the country in an army coup, replacing a previous dictator with himself. In 2014, with his help, the Sentinels of the New Dawn intended to cause an ebola epidemic to take power. (AUDIO: The Sentinels of the New Dawn)
Behind the scenes
In the real world, the independent Republic of Tanganyika existed only between 1962 and 1964, after which it became part of Tanzania. It was also located in East Africa, rather than West as in the Doctor Who universe.