The review, which was handled by the AAR, saw Karmarama beat Isobel and Kitcatt Nohr Alexander Shaw to secure the £1.5 million account. The business also includes the Biography and recently launched Crime & Investigation Channels. The channels are a joint venture between Sky Digital and A&E Television Networks in the US.
The History Channel has previously worked with the agency Aloha. Its change of strategy from above the line to through the line is understood to have fuelled the search for a new agency.
Karmarama's appointment also coincides with a change in strategy for the Biography Channel, which has switched from pure brand awareness to a more programme-focused approach.
Nicki Harris, the History Channel's head of marketing, said: "It was a difficult decision. Karmarama stood out because of its overall experience of the TV market. "
In May, the History and Biography Channels became the latest in the Sky Media portfolio to run interactive ads.