"Rome Total War: Alexander is the second expansion for the personal computer game Rome: Total War. It is set in an earlier time period, putting the player in the role of Alexander the Great. It begins with Alexander's ascension to the Macedonian throne in 336 B.C. and lasts for 100 turns, each of which, unlike the original game and the first expansion, Barbarian Invasion, do not represent six months (assuming that it follows Alexander's actual reign of thirteen years, each turn would represent nearly seven weeks). The game is much the same as the original Rome: Total War, but with fewer factions, different units, and a different map. The player's goal is to conquer 30 provinces, including key cities such as Tyre, Halicarnassus and Babylon, within the 100 turn limit."
Source: Wikipedia, "Rome:_Total_War:_Alexander," available under the CC-BY-SA License.