There are 81 provinces in Turkey (Turkish: il). Among the 81 provinces, thirty are designated metropolitan municipalities (Turkish: büyükşehir belediyeleri). Metropolitan municipalities are subdivided into districts (Turkish: ilçe), where each district includes a corresponding district municipality, which is a second tier municipality.
The first metropolitan municipalities were established in 1984. These were the three most populous cities in Turkey, namely; İstanbul, Ankara and İzmir. In each metropolitan municipality a number of second level municipalities (ilçe) were established. In 1986, four new metropolitan municipalities were established in Adana,Bursa,Gaziantep and Konya. Two years later the total number was increased to eight with the addition of Kayseri. In 1993, seven new metropolitan municipalities were established in Antalya, Diyarbakır, Erzurum, Eskişehir, Mersin, Kocaeli and Samsun.Following the earthquake of 1999, Sakarya was also declared a metropolitan municipality.
Before 2004, only the urban centers with a population more than 750,000 were declared metropolitan centers. However, in 2004, the concept of metropolitan municipality was redefined in Istanbul and Kocaeli, where from then on metropolitan municipality borders would overlap with provincial borders. In 2012, this was extented to other metropolitan municipalities. Thus, all provinces with a population in excess of 750,000 were declared metropolitan municipality and accordingly the number of metropolitan municipalities has sharply increased. The following 13 cities became metropolitan municipality: