Wikipedia dive complete!
General information:
Historical European Martial Arts.Swordsmanship.European styles:
Viking weapons and armor, sans horned helmets. They were lightly armored, and fought with a variety of weapons, from swords to spears to bows and arrows. They fought with a berserker/shock and awe style, emphasizing speed over suitability. They tried to escape before backup came. 8-11th century. Source on that.
De Re Militari, a roman book about warfare. It stayed relevant even after gunpowder. "Concerning Military Matters". Mostly dealing with running military campaigns. 5th century.
German school of swordsmanship. Focus on the two-handed longsword, but also discusses other martial arts.
Taking the shortest and most direct line of attack disregarding flourishes or flashy parrying techniques. (Less chance to parry, less chance to disarm, bonus to heavier weapons.)
Footwork and stance and of correct distance and speed of motion. (Better dodge chance.)
Taking the offensive, with a fixed plan of attack. (Bonus to initiative.)
Hiding the intended action from the opponent. (Bonus to surprise opponents.)
Speed and courage paired with wariness, deceit and cleverness. (Bonus to relevant stats.)
Correct distance, concealing one's intentions, reason, anticipation and dexterity. (Mostly repetition.)
Training and confidence, speed, agility and good footwork. (More repetition.)
Italian school of the same. An advanced system of grappling, daggers, poleaxes, short-swords, long-swords, and spears. There were many weapon combinations:
Sword alone
Sword and Dagger
Sword and Small Buckler
Sword and Broad Buckler
Sword and Targa
Sword and Rotella
Sword and Cape
Sword and Gauntlet
Two Swords
Sword for Two Hands (also referred to as the Spadone by some masters)
Dagger
Dagger and Cape
Halberd
Spetum
Ronca (weapon)
Partisan (weapon)
Partisan and Shield
Lance
Pike
Unarmed against Dagger
Ancient era:
Ancient Greek warfare. Mostly information about general strategies. 800-480 B.C.E.
Peltast, a type of light infantry. Focused on javelins. Originated in Thrace.
Hoplites, Greek spearmen. Fought with long spears and large shields. Armored. (Could receive bonus to fighting in groups, as they often used the phalanx.)
War in Mesopotamia. Little information, but I didn't look very hard.
I didn't look into Rome, as I thought that would be too advanced for your needs.
Also, almost every culture that used shields had a type of shield wall, going back to Mesopotamia.