Philopoemen of Megalopolis

Philopoemen reformed the Achaean League's military, introducing Macedonian-style tactics and equipment. He trained the infantry to use the sarissa pike and organized them into phalanxes, transforming the League's army into a more effective fighting force.

Philopoemen led the Achaean League to a decisive victory over Sparta at the Battle of Mantinea. The Spartan army was destroyed, and their leader Machanidas was killed. This victory broke Spartan power and established Achaean dominance in the Peloponnese.

Philopoemen captured Sparta and forced it to join the Achaean League. He dismantled the Spartan walls, abolished the Lycurgan constitution, and imposed Achaean laws. This ended Sparta's independence as a major power.

Philopoemen was captured by Messenian rebels while on campaign. He was imprisoned and forced to drink poison, dying at age 70. His death was a major blow to the Achaean League, which lost its most capable general.