The Crossbowman is much better armed than an Archer and a really solid unit overall. Its 30 Combat Strength enables it to stand its ground against Swordsmen, obliterate incoming Warriors and take only minor damage from Archers and Ancient Era city defenses. On the offensive side, 40 Ranged Strength provided by armor-punching crossbow bolts, combined with the Range of 2 lets you wreak havoc on your enemies with impunity all the way until the Industrial Era!
For players planning to wage an early war, the tech requirement for Crossbowmen can be beelined easily, as many of them have Eurekas that can be effortlessly triggered. This is especially dangerous in multiplayer games, when a few Crossbowmen often lead to the utter destruction of unsuspecting players. A single Crossbowman is also devastating as a garrison, practically doubling the already powerful Ranged attack of a city; get him the Garrison promotion for a terrific +10 RS which will allow him to one-shot non-promoted Catapults!
The crossbow – easier to master than the bow and hence perfect for peasants, who really didn’t have much time to practice archery – is in essence a small, heavy bow set crossways on a mechanism for drawing and releasing a short arrow (termed a bolt or quarrel). Invented in eastern China, it is first recorded in use during the aptly-named Warring States Period, c. 4th Century BC. The famed Sun Tzu devoted no less than two chapters in his influential 'Art of War' to the use of the crossbow. Around the same time, a sort of crossbow ancestor made its appearance in Greece, and the Romans may have used a few. But it is during the Middle Ages that the crossbow dominated the European battlefield. Combined with pikemen, another weapon that didn’t require a lot of skill to use, massed crossbowmen could turn aside almost any threat. The only downside to the crossbow was the skill necessary to construct one. But, until the advent of muskets, it was the best thing available to those unruly peasants.