Germany's East African possessions were internationally recognised in 1888. They came about because of Kaiser Wilhelm's desire for an empire to rival that of the British and French. Tanganyika was the only reasonable slice of real estate of any economic value gained for Germany. Togoland was too inhospitable; SW Africa (Namibia) was two-thirds desert.
Using the excuse of the suppression of slavery, German troops invaded in 1895, while the British laid siege to Zanzibar, the slavers' headquarters. Neither felt compelled to leave after their conquests.
Britain had a dream of a 'Cape to Cairo' railway. It took years of hard bargaining to consolidate the Kaiser's new empire.
Depending on what you read, Germany was either enlightened imperialists, spreading education and hospitals throughout East Africa or oppressors and exploiters reaping the vast resources of coffee and sisal for the benefit of German industry.
At best, I don't believe they were any better or worse than the British and a hell of a lot preferable than the Belgians in the Congo.
Gouveneur von Schnee and General Paul von Lettow-Vorbeck maintained the loyalty of the colony up until the armistice on November 1918. When von Lettow died in 1964 aged 94, Tanzanians provided the pallbearers at his funeral, some of whom served with him. I guess that illustrates the high regard he was still being held in East Africa after nearly 50 years.
Northern Rhodesia is present day Zambia. Tanganyika and Zanzibar constitute Tanzania today. Rwanda and Burundi (Urundi) were once incorporated in 'Deutsch-Ostafrika.' Lake Nyasa, (Njasasee in German) is now Lake Malawi. The words, Dar-es-Salaam, are run together in German and appear as Daressalam on all the old maps. The names, Bismarckburg and Abercorn have disappeared, they are modern day Kasanga and M'bala. Rungwa may have been called Ljyalas in colonial times but as I can't confirm it, I chose to call it by its modern name. At the end of the day, it's my story and I can do what I like.