This is a timeline of Tanzanian history, comprising important legal and territorial changes and political events in Tanzania and its predecessor states. To read about the background to these events, see History of Tanzania. See also the list of presidents of Tanzania.

Early Pleistocene Year Date Event 1.65 mya to 1.53 mya Oldowan stone tool culture at Olduvai Gorge.Leaky, Mary (1979). Olduvai Gorge. London, England: London: Book Club Associates. pp. 11–17, 40

3rd millennium BC Year Date Event 3000BC Evidence of indigenous pottery and agriculture dating as far back as this period is found in the Tanzanian coast and offshore islands.Felix A. Chami and Amandus Kwekason. Neolithic Pottery Traditions from the Islands, the Coast and the Interior of East Africa. African Archaeological Review, Vol. 20, No. 2, June 2003

6th century BC Year Date Event 600BC International trade goods including Graeco-Roman pottery, Syrian glass vessels, Sassanian pottery from Persia and glass beads dating to this century are found at the Rufiji River delta.

1st century BC Year Date Event 1000BC – 300AD The earliest settlements in the Swahili coast appear on the archaeological record in Kwale in Kenya, Misasa in Tanzania and Ras Hafun in Somalia.Chap Kusimba and Randal Pouwells. The Rise and Fall of Swahili States. The International Journal of African Historical Studies 33(2):437. DOI: 10.2307/220701. Available from: https://www.researchgate.net/publication/274126407_The_Rise_and_Fall_of_Swahili_States/link/58cbce7c458515b6361d58ee/download

1st century AD Year Date Event ~1AD – 50AD The Periplus of the Erythrean Sea, a Graeco-Roman manuscript is written. It describes the East African coast (Azania) and an established Indian Ocean Trade route

2nd century AD Year Date Event 100AD – 600AD Centuries ahead of European metallurgists, the Haya people from the western shores of Lake Victoria manufacture carbon steel.Schmidt, P.; Avery, D.H. (1978). "Complex iron smelting and prehistoric culture in Tanzania". Science. 201 (4361): 1085–89. Bibcode:1978Sci...201.1085S. doi:10.1126/science.201.4361.1085. . S2CID 37926350

4th century AD Year Date Event 300AD – 1000AD Growth of Azanian and Zanj settlements in the Swahili coast. Local industry and international trade flourish.

7th century AD Year Date Event 614AD – 900AD Starting with the first Hijrah (migration) of Prophet Muhammad's followers to Ethiopia, Islam spreads across Eastern, Northern and Western Africa.Hussein D. Hassan. CRS Report for Congress. Islam in Africa. Available from: https://sgp.fas.org/crs/row/RS22873.pdf 630AD – 890AD Archaeological evidence indicates that crucible steel is manufactured at Galu, south of Mombasa. Metallurgical analysis of iron artefacts indicates that the techniques used by the inhabitants of the Swahili coast combined techniques used in other African sites as well as those in West and South Asian sites.Chap Kusimba. HE SOCIAL CONTEXT OF IRON FORGING ON THE KENYA COAST. Africa: Journal of the International African Institute, Vol. 66, No. 3 (1996), pp. 386–410

11th century Year Date Event 1000AD – 1500AD Emergence of the Swahili City States.Pradines, Stephane. "Islamization and Urbanization on the Coast of East Africa: recent excavations at Gedi, Kenya." Azania vol. 38 (2003): 181. https://dx.doi.org/10.1080/00672700309480369 1000AD – 1200AD The oldest Swahili texts in existence date to this period. They are written in old Swahili script (Swahili-Arabic alphabet) based on Arabic letters.

12th century Year Date Event 1178–1195 Suleiman Hassan (c. 1178–1195), conquers the rival nation of Sofala.

13th century

14th century Year Date Event ~1331 Moroccan explorer Ibn Battuta visits Kilwa.Ibn Battuta's & Zhao Rugua's East African Travels (Excerpts) http://users.rowan.edu/~mcinneshin/5394/wk05/battutaTVLsEAFR.htm

15th century Year Date Event 1400–1500 The ancestors of the Iraqw are credited as the builders of the Iron Age settlement at Engaruka in Northern Tanzania. Complex irrigation systems supporting intensive agriculture supported an estimated peak population of 40,000. It is recognised as the largest abandoned system of irrigated agricultural fields and terraces in sub-Saharan Africa."Lost city" used 500 years of soil erosion to benefit crop farming. University of New York Department of Archeology. Available from: https://www.york.ac.uk/archaeology/news-and-events/news/external/news-2017/engaruka-soil-erosion/Stump, Daryl (2006). "The development and expansion of the field and irrigation systems at Engaruka, Tanzania". Azania. 41: 69–94. doi:10.1080/00672700609480435Laulamaa, Vesa (2006). "Estimation of the population of ancient Engaruka—a new approach". Azania. 41: 95–102. doi:10.1080/00672700609480436 1410 Kilwa's ruler makes a recorded pilgrimage to Mecca. 1498 25 February The Portuguese explorer Vasco da Gama is the first known European to reach the East African coast, landing at Kilimane, where he stayed for 32 days.

16th century Year Date Event 1505 24 July Sack of Kilwa by the Portuguese Empire marking an end to the Kilwan golden age in the Swahili coast. 1505 August Captain John Homere, part of Francisco de Almeida's fleet, captures the archipelago of Zanzibar, making it part of the Portuguese Empire.

17th century Year Date Event 1698 Zanzibar falls under the control of the Sultan of Oman. 1698 Oman's conquest of Kilwa leds the Yao to flee to Mozambique island. 1700 Over 100,000 slaves pass through Zanzibar as part of the Arab slave trade.

18th century Year Date Event 1700 The founding of the Chagga states of Kilimanjaro.Dundas, Charles. Kilimanjaro and Its People: A History of Wachagga, their Laws, Customs and Legends, Together with Some. Routledge, 2012. 1776 Kilwa was reviving and becomes East Africa's largest slave port with the Yao returning from Mozambique as slave taders. The enslaved were sold to the French colonies of the Mascarene islands. 1776 Smallpox plagues southern Tanzania.

19th century Year Date Event 1819 The Shambaa Kingdom enters a golden age under Kimweri ye Nyambai's reign. 1820 Famine in Ukerewe. 1822 United Kingdom signs the Moresby Treaty with Sultan Seyyid Said to begin the abolition of slavery in Zanzibar. 1840 December Omani Sultan Seyyid Said moves his capital to Zanzibar City. 1842 Ngoni king Mputa Maseko arrives and settles in Songea. While Zwangendaba settles in Ufipa. 1843 The last Sultan of Kilwa is deported to Oman. 1848 11 May German missionary Johannes Rebmann, accompanied by Johann Ludwig Krapf, become the first Europeans to report seeing Mount Kilimanjaro. 1850 The Zigua burn Saadani to the ground. 1850 Swahili is spoken widely among the Gogo and Sagara. 1855 King Muyigumba conqueres the northern and central Hehe chiefdoms into a unified Hehe state. 1856 Sultan Seyyid Said dies at sea and is succeeded by his sons Thuwaini bin Said, in Muscat and Oman and Majid bin Said, in Zanzibar. 1857 26 June British explorers Richard Burton and John Speke travel from Zanzibar to the East African coast and begin their exploration of continental East Africa. 1857 Maize is grown in the Pangani Valley. 1858 13 February Burton and Speke reach Lake Tanganyika, the first known Europeans to do so. 1860 King Mirambo of the Nyamwezi rises to power. 1861 2 April Zanzibar and Oman are split into two separate principalities with Majid bin Said becoming the first Sultan of Zanzibar. 1863 Songea's king Mputa Maseko is killed by dissident Ndendeuli who flees east to the Kilombero valley and recreates Ngoni style military state forming the Mbunga people, forcing the Pogoro to flee eat to the Mahenge plateau. 1863 The French Holy Ghost Father established their first church in Zanzibar and move it to Bagamoyo in 1868. 1869 The Kiva rebellion, where Bondei rebel against the Shambaa Kingdom's rule. 1870 Islam becomes the major religion among the Zigua and Bondei. 1873 Zanzibari Sultan Barghash bin Said stops the export of slaves over the sea. 1874 Civil war in the Shambaa Kingdom turns Pangani into a rival slave port to Bagamoyo and Kilwa. 1875 Bagamoyo pays tribute to the Zaramo fearing attack. 1875 The Mbugu of Gare kill a Kilindi royal in rebellion. 1876 Barghash bin Said closes Zanzibar's slave market. 1876 Kilwa's biggest export switches from slaves to wild rubber. 1878 The Hehe and Ngoni go to war with the Invasion of Mshope by the Hehe. 1880 Fipa King Kapufi of Nkasi hires an Arab Prime minister in his court. 1881 The Pare at Mbaga attack a slave trader settlement of Kisiwani. 1882 The Ngoni and Hehe end their war with Bena partitioned amongst them as a buffer. 1882 King Songea Mbano of the Ngoni raids the eastern stateless peoples like the Ngindo, Makonde and Mwera forcing them to flee further eastwards leaving empty land. 1884 28 March The Society for German Colonization is formed by Karl Peters in order to acquire German colonial territories in overseas countries. Peters signs treaties with several native chieftains on the mainland opposite Zanzibar. 1884 23 November The Germans led by Peters land at Saadani and start the invasion reaching the Ngulu mountains and signing a sham treaty with Chief Mafungu Biniani of Ngulu . 1884 2 December Mirambo of the Nyamwezi empire dies. 1885 3 March The German government announces its intention to establish a protectorate in East Africa. 2 April The German East Africa Company is formed by Karl Peters to govern German East Africa. 1886 1 November An agreement is reached between Britain and Germany designating a wide strip of land along the coast as being controlled by Sultan Barghash bin Said, along with Zanzibar, Pemba, and Mafia. The area that is to become Tanganyika is assigned to Germany while the area to become Kenya is assigned to Britain. 1887 25 May The Germans occupy Dar es Salaam. 1887 The Zaramo attack two German stations in Dar es Salaam . 1888 April The German East Africa Company leases the coastal strip opposite Zanzibar from Sultan Khalifah bin Said for 50 years. 1888 The Zigua boycott a station in Old Korogwe. 1888 September Tanga is bombed by German warships. 1889 June Germans capture Saadani after fierce fighting Bwana Heri flees inland . 1889 July Germans capture Pangani after heavy shelling from the sea. 1889 15 December Germans hang Abushiri . 1890 1 July The Heligoland–Zanzibar Treaty makes Zanzibar and Pemba a British protectorate. 1 August The Sultan of Zanzibar signs an anti-slavery decree. 1890 1 May Germans bombard Kilwa for three days into submission. 1891 February The Battle of Kibosho. 1891 November Mangi Rindi dies. 1896 27 August The Anglo-Zanzibar War is fought between Zanzibar and the United Kingdom. It lasted approximately 38 minutes and is the shortest war in history. 1896 November The Germans and Chagga sack Meru. 1897 5 April Sultan Hamoud bin Mohammed issues a decree making slavery illegal in Zanzibar. 1897 Mangi Sina dies. 1898 19 July Following years of resistance, Chief Mkwawa of the Hehe is cornered by German soldiers and commits suicide in lieu of capture. 1898 Katukamoto of Urambo, who was held accountable for the murder of an askari, was imprisoned. Following this event, the remnants of Mirambo's empire were systematically dismantled.

20th century