Specialized in defeating Knights and other mounted Units.
The Pikeman is a more powerful Spearman. It receives a bonus when fighting against mounted units, which makes it pretty much the only unit that can hope to stand up against a rampaging Knight. A Pikeman fortified in defensive terrain is a Knight's worst nightmare.
A pikeman is a better-trained and armored spearman armed with a longer, sharper weapon. Unlike the shorter and lighter spear, a pike is almost always used two-handed. Historically pikemen were most effective against other infantry and cavalry, but as they lacked shields, they were quite vulnerable to archers.