In 1869, German missionaries established the first German presence in the territory that would become German East Africa. In 1884, the Company for German Colonization was founded by German explorer Carl Peters, and immediately began establishing treaties with local chiefs in the coastal region.

Over the next decade, the newly-founded German East Africa Company would increase German influence in the area by opening customs houses and forming agreements with local chiefs and Sultans. In the last years of the 1880s, however, Arabs opposed to the increased European presence began raiding and killing German settlers. The German East Africa Company requested assistance from the Imperial government, which quickly came in the form of ships and men under the command of newly-appointed Imperial Commissioner Hauptmann Hermann von Wissmann. Within a year, the insurrection was crushed, and in 1891, Germany acquired sovereignty over the entire territory.

A postal agency was first opened at Tanga on 5 May 1891.  Due to its location on the coast and on the Usambara Railroad, Tanga was one of the largest and busiest post offices in the colony.  The post office remained open until 7 July 1916, when British forces captured Tanga.