The foundation of İller Bankası A.Ş., which assumed important duties and responsibilities in the reconstruction and construction of their cities and towns within the framework of the development initiative initiated after the War of Independence, was established by the instructions of their Great Leader Mustafa Kemal Atatürk;

• It was established under the name of 'Municipalities Bank' with a capital of 15 million on 11 June 1933, with the Law No. 2301, in order to finance the development activities of the municipalities.
• In accordance with the Establishment Law, the Bank's activities only for municipalities, the inability of its founding capital to meet the increasing need for loans in parallel with rapid population growth and urbanization, and the exclusion of Special Provincial Administrations and villages in need of financial resources and technical assistance from this aid and the expansion of its field of activity should be taken into consideration. It was thought that the Municipalities Bank would have a different structure, and the draft law submitted to the Grand National Assembly of Turkey on 29.07.1944 was prepared in order to transform the Municipalities Bank, which was established with this thought, into the Local Administrations Reconstruction Bank. During the discussion of this draft in the Budget Committee, the name of the Bank was changed to 'Iller Bank'.
• The establishment of the General Directorate of Iller Bank, which includes Special Provincial Administrations, Municipalities and Villages, was officially established by assuming the duties of the Municipalities Bank with the enactment of the Law No. 4759, which was accepted on 13.06.1945 and published in the Official Gazette on 23.06.1945.
• With the law numbered 6107, which was accepted by the Grand National Assembly of Turkey on 26.01.2011 and published in the Official Gazette dated 08.02.2011, "Iller Bankası A.Ş." got its name.
• Iller Bank Inc. It is a development and investment bank with the status of a joint stock company with a legal personality and a special budget, subject to the provisions of private law.