The coastal region is described in the Periplus of the Eritrean Sea, an ancient document from an anonymous Greek navigator written in the I-II century b.C.; it is also indicated by the name of Azania; already during those distant times it was the destination of trade with the Arabian Peninsula and the East.
 
It became, probably by the end of the seventh century a.C., settlement home to islamized Arab and then to the Persian from Shiraz who founded in the tenth century a.C., the burgeoning empire of Zengi (ie the Blacks), that lasted until the advent of the Portuguese.
 
Arab and Persian, amalgamated with the native populations of the coast and inland, particularly Bantu and Zulu, gave birth to the Swahili language and culture that featured then all the society of that geographical area.
 
The Portuguese, in search of support and trading posts on the route to India, appeared on the coast of the current Tanzania in 1498 and settled in the main towns.
 
With the Arab revolt of Mombasa in 1631 began for Portugal a struggle lasted until the fall of Fort Jesus (1698), of Pemba and Kilwa.
 
At the beginning of the eighteenth century a.C. the domination of the entire coastline North of Mozambique passed into the hands of the Sultan of Oman, who entrusted the various centers to his family members, who, however, sought to become independent.
 
In 1828 Seyd Sa'id reasserted his authority from Mombasa and moved the seat of the principality to Zanzibar.
 
Sa'id found substantial support in Great Britain with which he signed a treaty that provided as compensation the abolition of the slave trade.
 
Sa'id Bargash, who was sultan from 1870 to 1888, extended his control to the interior regions of Tanzania, reaching the Great Lakes region with the intent to discourage slave traders, in collaboration with England he also tried to open the country to the outside world.
 
In the nineteenth century, the great explorations were undertaken, particularly in the second half of the century even by missionaries and German agents; remarkable is the action carried out by K. Peters through the German East Africa Company.
 
These expeditions led, in 1884, to the signing of a series of treaties that secured advantageous terms to the German Society of East Africa and led, in 1885, the territory of today's mainland Tanzania under the protectorate of Germany, creating legal separation of Tanganyika, the mainland, from Zanzibar and Pemba; nothing worth the opposition of the Sultan Sa'id Bargash.
 
Successive agreements in 1886 and 1890 defined in detail the zones of influence of Germany and England on Tanganyika and Zanzibar territories and towards the Sultan of Zanzibar.
 
In the following years, however, the Germans had to face numerous riots fomented by the Arab element and the diehard native populations, revolts that lasted until 1907.
 
The policy of Germany, to give an organization and a development to Tanganyika, was very effective but was soon interrupted by the outbreak of World War I.
 
General von Lettow Vorbeck was able, with his modest actual people, to stand up to the British and Belgian forces until November 1918, the date of the signing of the armistice that decreed the defeat of Germany in World War I.
 
The German East Africa's land was given, by the Allied Supreme Council, as term B, and then legitimized by the League of Nations, to Great Britain regarding the territory of Tanganyika and to Belgium, the territory of Rwanda-Urundi.
 
In 1920 and 1926 were established in Tanganyika respectively the first Executive Council and the first Legislative Council.
 
After World War II, the mandate was transformed into Trusteeship of the United Nations on December 13, 1946.
 
The constitutional reforms of 1948 and 1954 favored the Tanganyika political evolution and the emergence of a nationalism that found in J. Nyerere and the Tanganyika African National Union, TANU, a moderate but effective support.
 
The foundations were laid for the recognition of the establishment of modern Tanzania.