The company was established in 2001 to consolidate and manage the majority stake of the commercial Bank Unionbank AD. In 2006, the Group consolidated the companies Union Property EAD, Union Electric EAD and Union Tours OOD, aiming to manage 100% of the owned shares. In the middle of the same year, Union Group AD sells 51% of its shares in Unionbank AD to the third largest bank in Hungary MKB Bank, part of the Bayerische Landesbank group, a leading bank in Germany and № 1 Bank in Bavaria.
In the period of its existence, Union Group AD increased its share capital more than once to reach the present amount of BGN 20 640 000.
1991 - The current owners of Union Group AD - Ivan Radev, Emanouil Manolov, Emil Ivanov and Svetoslav Radev founded Boras OOD. The company is licensed by the BNB as one of the first foreign currency trading companies.
1992 - Boras OOD creates Financial Brokerage House Sofia AD.
1992 - Financial Brokerage house Sofia AD is licensed by the BNB as a non-banking financial institution.
1994 - Financial Brokerage House Sofia AD was re-registered, renamed and licensed by the Bulgarian National Bank as Commercial Bank Unionbank AD, thus becoming its historical and legal successor, a fact unique to the latest financial history of the country.
1999 - Union tours OOD jointly with Industrial Holding Bulgaria AD purchases through the Privatization Agency the majority stake in Dunav Tours AD, exercising joint control over its management.
2001 - Ivan Radev, Svetoslav Radev, Emil Ivanov and Emanouil Manolov founded Union Group OOD, transformed later in 2007 into a joint-stock company.
2002 - The European Bank for Reconstruction and Development (EBRD) acquires 15% of the share capital of Unionbank AD.
2005 - The private shareholders, founders of CB Unionbank AD, consolidate their own shares and those of Union Group, as a result of which Union Group gained control of 85% of the share capital of the financial institution and the remaining 15% are owned by the EBRD.
2006 - In May, the deal for the purchase of 60% of the share capital of Unionbank AD from the third largest bank in Hungary, ICB Bank, was finalized. The bank is part of Bayerische Landesbank Group, Germany's leading bank and № 1 Bank in Bavaria, which currently manages assets of more than EUR 350 billion. After the sale of the shares, the distribution of the capital of Commercial Bank MKB Unionbank AD is as follows:
MKB Bank - 60.00 %
Union Group OOD - 19.86 %
Boras OOD - 14.14 %
EBRD -  6.00 %
Union Group OOD and Boras OOD, holding a total of 34% of the share capital of MKB Unionbank AD, are protected by the agreement between the shareholders of the Bank.
2006 - Union Group OOD purchases 100% of the capital of Union Tours OOD.
2006 - Union Group invests the funds from the sale of the shares of the bank in the following directions: 
Real estate – the activity is carried out by Machinveks OOD, later in 2007 transformed and renamed to Union Property EAD. The share capital of the company has been increased over the years to the present amount of BGN 16 212 500.
Energetics – the activity is carried out by Mashbuild OOD, later in 2007 transformed and renamed to Union Electric EAD. The share capital of the company has been increased over the years to the present amount of BGN 17 693 310;
Ship ownership and river cruise tourism – the activity is carried out by Union Tours EOOD through Dunav Tours AD;
2005-2007 - Union Tours EOOD, through Dunav Tours AD, realizes a large investment related to the acquisition of three luxury passenger ships, the newly built  motor boat Rousse Prestige in the Netherlands and the purchased  motor boats Heinrich Heine and Elegant Lady.
2007 - The subsidiaries "Union Property" EAD and "Union Electric" EAD carry out significant investments in the respective business fields.
2007 - "MKB Unionbank" AD significantly increases its share capital - from BGN 15 411 765 to BGN 40 411 765.
2008 - "MKB Unionbank" AD increases its share capital by BGN 20 000 000 from BGN 40 411 765 to BGN 60 411 765.
2009 - The subsidiary Union Tours EOOD is merged with the parent company Union Group AD
2009 - Union Group AD and Boras OOD sell their share of 34% of the capital of MKB Union Bank AD to the Hungarian MKB Bank.
2012 - Union Group AD acquires control over Dunav Tours AD after acquiring another 48.44% of its shares, as a result of which Dunav Tours acquires the status of a subsidiary of Union Group AD.
2012 - Dunavsko Rechno Plavane EAD, a subsidiary of Dunav Tours AD, puts into operation a new luxury passenger ship "Ariana" (4+). The ship was built in the Netherlands and has 101 cabins, from which 81 for passengers.
Over the years, from 2009 until now, Union Group AD continues to actively invest in the core business areas of its activities: "Energetics", "Real Estate" and "Ship ownership and River Cruise Tourism"