There are 8 scenarios in the Battles of the Conquerors campaign:
1. Tours (732)
2. Vinland Saga (1000) – misspelled Vindlandsaga in-game
3. Hastings (1066)
4. Manzikert (1071)
5. Agincourt (1415)
6. Lepanto (1571)
7. Kyoto (1582)
8. Noryang Point (1598)
Win every scenario of the campaign using the cheat code “i r winner”. Then, to trigger the achievement, win any scenario of any campaign without using cheat codes. The quickest scenario is the 1st scenario of the William Wallace Learning Campaign: Marching and Fighting.