Medieval Era front-line unit. Upgrades from Swordsman. Requires Iron.
The next level front-line unit, the Longswordsman is equipped from head to toes with the finest full-plate armor, and wields a two-handed sword capable of overwhelming the most experienced foot soldiers of the Medieval Era. Longswordsmen are indisputable masters of melee combat against earlier fighters, who often can't even scratch their armor, and thus offer great protection to other units. Their prowess is such that they remain useful well into the Renaissance Era, even against the new gunpowder units.
Still, Longswordsmen are not without drawbacks. Aside from requiring Iron, they remain vulnerable to sustained ranged attacks from modern Crossbowmen and Trebuchets, and they can be outmaneuvered by mounted units. Furthermore, since the Musketmen that become available immediately afterward are stronger and do not require strategic resources, it is often advantageous to go straight for Gunpowder rather than raising a large army of Longswordsmen.
The longsword was the most versatile weapon of the Medieval/Renaissance battlefield. It was lighter and easier to carry than a pike, and it could be used one or two-handed, making it possible for the swordsman to also carry a shield. In face-to-face combat against pikemen the longswordsmen were at a significant disadvantage, taking many casualties from the longer weapons before they could even get within striking distance. However, longswordsmen units were faster and more maneuverable than pikemen - and if they could hit their opponents in a flank attack, the pikemen were dead meat.
Longswordsmen are iconic of the Middle Ages, despite enjoying a relatively short period of dominance before widespread plate armor and later gunpowder saw their decline on the battlefield. The sword was held with two hands and could be used by an agile wielder to keep lesser infantry at bay; this inherent speed made the longsword ideal for unarmored combat. However, longswords were often reserved for the nobility as they were expensive to make and required a skilled smith to ensure a good quality blade.