The initial nucleus of the Collections belonging to the Historical Archives Department was made up of the archives of the Hellenic Industrial Development Bank (ETBAbank), as well as those of the Tourist Credit Organization (TCO), the Economic Development Financing Organization (EDFO) and the Industrial Development Corporation (IDC), from whose merger ETBAbank came into being.

By receiving the archives of ETBAbank's holding companies, but also through this bank's incorporation into the Piraeus Bank Group, the Historical Archives were enriched with new important archives belonging to the Group. 

The archival material is constantly being expanded with new collections and donations and is managed according to international archival standards.

The Department's collections comprise historical documents originating from:
 
- the Piraeus Bank, which was founded in 1916 under the company name "Banque du Piree pour le Commerce, l'Industrie et la Navigation";

- the Chios Bank, established in 1919 by bankers N. Paspatis, Philippos Chryssovelonis and Alexandros Paspatis, lawyer Pavlos Katsoyannis and private sector employee Andreas Saounatsos; 

- the Tourist Credit Organization (TCO), set up in 1946 so as to provide loans for the hotel and tourist industry with a view to exploiting and developing the country's tourism potential. The archive's material concerns the development of tourism in Greece through the granting of loans and credit lines to hotel ventures and tourist agencies and covers the entire period of the Organization's operations, from 1946 through to 1964;

- the Central Loan Committee-CLC (search), which functioned between 1949 and 1954 and was responsible for the management and granting, via banks, of industrial and agricultural loans under the four-year reconstruction programme (Marshall Plan), as well as for managing the loans granted by the American Mission for Aid to Greece (AMAG). The fonds material concerns Greece's economic reconstruction in the agricultural and industrial sectors, from 1949 through to 1954;

- the Economic Development Financing Organization-EDFO (search), which replaced the Central Loan Committee after its dissolution in 1954 and was founded following an agreement signed between the Greek government, the Bank of Greece and the American Mission in Greece. Except for managing the loans granted by AMAG and CLC and the new American aid programmes, EDFO was also responsible for granting long-term loans to industrial, mining, agricultural and tourist ventures, as well as for supporting the special programmes of the Agricultural Bank of Greece and the National Mortgage Bank of Greece. Important corporations, such as the Skaramangas Shipyards, Halyvourgiki Inc. (steelworks) and Lignitorycheia Ptolemaidos (Ptolemais lignite mines), received EDFO loans. The fonds covers the Organization's activities throughout the period of its functioning, from 1954 to 1964; 

- the Industrial Development Corporation (IDC), was established at the end of 1959 as a public agency for the design and promotion of industrial development works. In collaboration with foreign consultants, IDC elaborated a series of industrial works designs, such as the organization of the industrial zones of Thessaloniki, Kavala, Volos, Patras and Heraklion, and participated in the creation of a number of large industries, chief among them Aluminium of Greece S.A., Grecian Marbles (Marmor) Ltd., Hellenic Industry of Construction Materials S.A. and Metallikai Kataskevai (Metallic Constructions, today METKA S.A.). The fonds covers the whole of the period over which the Corporation functioned, from 1960 through to 1964;

- the Hellenic Industrial Development Bank (ETBAbank), which was founded in 1964 through the merger of TCO, EDFO and IDC with the objective of promoting "the country's industrial or cottage-industry, mining and tourist development". With an initial capital that was greater than the sum of all of the Greek banks' capital and reserves, ETBAbank was one of the most dynamic banks among the European Mediterranean countries and played a determining role in the development of Greece's industry, merchant marine and tourism. The ETBAbank fonds covers the period commencing with the Bank's establishment and is constantly being enriched with new documents from the Bank's inactive records. 

- the holding companies of ETBAbank, as well as of the companies that were liquidated by the ETBAbank Group, a number of which were founded in the early 20th century, e.g. Piraiki Patraiki Cotton Manufacturing S.A., Hephaistos Mineral and Industrial Company S.A., Hellenic Textiles S.A. These archives are among the basic sources for the study of Greece's industrial and economic history, while an important number of company archives will also be received in the near future from the ETBAbank Group.

The Historical Archives' collections also include historical documents that came into its possession through donations: 

- the Archives of Anastassios and Stefanos Konstas, which contain documents, plans and photographs of their industrial design and installations consultancy that concern the sectors of the olive-oil producing industry and the industry of petroleum products in Greece and abroad;

- the Archives of Peteinaris Brothers Machinery Manufacturers, who produced diesel and petrol engines and machinery for olive presses, in digital form (mostly photographs), and which were donated by Danae Kalogeraki-Peteinari.