The final installment chronicles the centuries of war leading up to the Norman invasion. This was an era defined by power-hungry Vikings, Irish kings preoccupied with their own dynastic battles, the reign and murder of the high king Brian Boru, and Rome's campaign to stamp out corrupt practices within the Celtic church. "Warlords" explores 150 years of rivalry between various factions seeking control of Ireland, and the arrival and interference of England's King Henry II. This is the great watershed of events as the English throne now claims supremacy over Ireland and the Irish -- a complex and bitter legacy whose repercussions continue to the present day.