The studio is responsible for the medieval-themed MMO strategy title of the same name on browser and mobile. Across its portfolio of 25 titles the company has more than 45 million users worldwide.
From January to August 2018 Imperia Online generated €4.1 million ($4.8m) in net revenue with a 48 per cent operating margin.
Stillfront’s acquisition sees it buy out 100 per cent of shares in the company. €5 million euros ($5.8m) will be payable in cash while a further €5 million ($5.8m) well be paid via 269,412 newly issued shares in the company.
The deal could rise to €27.5 million ($32.3m) due to earnouts based on the studio’s performance over the next three years.
“Imperia Online fits perfectly into Stillfront's growth strategy by broadening our portfolio of studios and games with characteristics that drive long-term gamer relations,” said Stillfront CEO Jörgen Larsson.
“Imperia Online is a leading developer and publisher with a solid and highly loyal user base. It is with pleasure I today welcome Dobroslav, Moni, Cvetan and the whole team at Imperia Online to the Stillfront family.”
Imperia Online CEO Dobroslav Dimitrov added: “Becoming part of Stillfront Group enables us to continue our development of new products within online strategy games. We see this acquisition as a strategic next step for Imperia Online, and we look forward to share market knowledge and create synergies with the other studios of the Stillfront Group.”
Agnitio Capital acted as financial advisor to Imperia Online for the deal.
Stillfront Group has built up a network of developers and publishers. Previous acquisitions include Hamburg-based studio Goodgame, German sports management game OnlineFussballManager, Dublin developer eRepublik Labs and MENA publisher Babil Games.