Below is the chronological history of the area:
12^th B.C. Occupation of the Briggs
7^th Domination of the Bithinians
547-546 Principalities of the Lydians
7^th to 560 A.D. The Byzantine Era. Emperor Justinian I (The Great) builds a bridge over the River Sakarya (ancient River Sangarios).
11^th century was the time when the area was divided into two regions with the border control castles built on both sides of this river by the Byzantines and the Selçuk Turks.
1071 Selçuk Era.
1313 Ottoman Turks capture the whole area.
1536 a village
1559 a sub-town
1646 a town
1658 a village again
1692 a town again
19^th century: Migration of the various peoples because of Crimean War, Sheyh Shamil incident and Ottoman-Russian War.
1837 a town attached to İzmit Province during the reign of Ottoman Sultan Mahmut II
1868 Establishment of Municipality
1877-1878 Dense migration from Caucasus and Balkan areas
1890 Connection of İzmit and Arifiye rail roads.
June 21, 1921 Liberty Day of Adapazarı from Greek invasion
1954 Sakarya becomes a province and Adapazarı a city.
1999 Severe earthquake in Adapazarı (In this earthquake 18000 people were killed and 25000 people were bodily and mentally injured)
2001 Adapazarı becomes a metropolitan city

Literally translated, the meaning of 'Adapazarı' is 'The Market Area or Bazaar of Island'. The reason that this name was given to the city was that during the 14^th century (during the reign of the Ottoman Sultan Orhan - the second emperor of the Ottoman Empire), this place, which was taken from the Byzantines, was called Island Village. Later, the village was expanded by 12 local families, and upon the improvement of agriculture, the area was atrracted by their various markets. In the 16^th century, the increase of the population caused this area to be a town.

Adapazarı, which became the metropolitan city of Sakarya Province on 17 June 1954, was hit by a severe earthquakes on 17 August 1999 which killed 3988 people, 5180 people were injured and 81702 accommodation and business properties were destroyed in different levels just within the Sakarya Province.
Abridged and translated from the website of the Metropolitan Municipality of Adapazarı by K. Can Arman.