- Messina and the Mamertines (228 BCE): Agathocles, Tyrant of Syracuse and (according to him) King of Sicily, hires the Italian mercenary gang the Mamertines. When they arrive in the town of Messina, on a little island between Italy and Sicily, they realize it is nice and keep it for the next 20 years. This will have a big effect on the First Punic War later on, because the Romans will have to go defend these now-Italian Mamertines from an attack by Carthage. Now, a little while later, there is no Carthage.
- Treason of the Long Knives (5th century CE): One of the most popular cautionary tales in English literature. Celtic king Vortigern hires the Jutish mercenaries Hengist and Horsa to help them fight the Picts and the Gaels. Instead England is now called England.
- Battle of Talas, 751 CE: Talas, in modern day Kazakhstan, plays host to a battle between the Abbasid Caliphate and the Tang Dynasy of China. This latter force is mostly comprised of Karluk mercenaries. They switch sides during the actual fight and kill the men beside them.
- Bosworth Field (1485 CE): This is the last battle of the civil Wars of the Roses between the houses of Lancaster and York. Henry Tudor opposes Richard III. But there is a third force on the field: Baron Stanley's mercenary army. Richard III is holding Stanley's son, Lord Strange, as a hostage, so he has to be very sneaky and is. Stanley holds back to see who will win, then switches sides. Henry Tudor becomes Henry VII, who fathers Henry VIII. Influential!
- Battle of Plassey, 1757 CE: In this horrific battle wherein the British slaughters elephants and gets going on their mission to seize the entire subcontinent, the East India Company fights the Nawab of Bengal and the French. Unfortunately for the world Nawab Sirah-ud-Daulah has recently demoted and upset his deputy, Mir Jafar. The British pays Mir Jafar and his friends to stand and do nothing doing the battle.
No conclusions can be reached.