Britannia
"Strive to become King of England in this battle game for control of Britain"
Britannia is a strategy board game published by Avalon Hill. Play starts at the Roman invasion in 45 AD, and continues until the aftemath of Battle of Hastings and Battle of Stamford Bridge (both 1066), ending in 1085 AD. The players take control over various nations, fighting for control over Britain in its historically most turbulent times.
Each nation (Romans, Romano-British, Belgae, Welsh, Brigantes, Picts, Caledonians, Irish, Scots, Norsemen, Dubliners, Danes, Jutes, Norwegians, Saxons, Angles and Normans) has its own agenda, based on its historical extent in time and space. They are divided in a specific way between the four players*, so that each nation is "surrounded" by opposing nations. This way, the nations are forced to think about their own goals, rather than the overall goals of the player (there are execptions to this).
The gameboard is a map over England, Scotland and Wales (with expansions adding Ireland, AFAIK). Each country is divided into areas, which the various peoples get points for holding. You also score points for killing specific enemies, or specific historical persons.
In my opinion, this is one of the best games made by Avalon Hill. It is very well balanced, and allows for many different strategies by each player. And even though the first three turns may seem hopeless to the non-Roman players, they each get other major invasions in turn. Luck enters the picture (as in many games), but it doesn't control the game completely. On the downside, it is all but impossible to decide who is winning before the game ends, making it impractical to stop the game short of its 4-5 hour playing time. All in all, a very recommended game.
*) It is possible to play with three or five players as well. Personally, I haven't tried playing with five, but the three player game is definitely unbalanced. Your nations simply become to close to each other, and can quite easily cooperate. If you are three players, play G.O.O.T.M.U. instead.