Stronghold is a historic real-time strategy (RTS) game developed by Firefly Studios in 2001. The game focuses primarily on conquest and expansion through military pursuits, but also provides space for economic strategy and development. There is both an economic and a military campaign to be played and both are discussed in the game manual. The game takes place in Medieval Britain around the time of AD 1066, though, since there is not always a time limit, scenarios can continue hundreds of years beyond that date.
As well as earning many favourable reviews from reviewers such as PCGamer and GameSpy (see Reception section), the game continues to boast a large community, who edit and create various material through the in-game Map Editor/Scenario Creator
Source: Wikipedia, Stronghold (2001 video game), available under the CC-BY-SA License.