Eidos Interactive is the publishing company that has published the Thief Series.
Edios Interactive itself was formed in 1996 by the acquiring and merger of English game publisher Domark (formely Antrocrown), Simis, and Big Red Sofware by Eidos PLC. Eidos merged Simis and Big Red into Domark to created the Eidos Interactive subsidary group. It later acquired CentreGold (CentreSoft & U.S. Gold, Core Design and Sillicon Dreams).
In 2000, Looking Glass Studios closed during a financial crisis related to Eidos, though LGS designer, Warren Spector, was able to move most of LGS's staff to Ion Storm Austin, a company bought by Eido Interactive in 1999.
In 2005, they were losing money and were taken over by fellow British games publisher/developer, 'SCi', merging with Eidos Parent group to create SCi Entertainment Group Limited. In 2007, they opened a new studio in Montreal, Quebec, named Eidos Montreal. They also bought Rockpool Games, which they closed in 2009. In 2008, SCi revealed more huge looses, along with the opening of their new studio in Shanghai, Eidos Shanghai, before closing the Manchester Studio. They were then sold to Square Enix.