The Saxons Were Brought to England as Mercenaries
As the Roman Empire came under mounting pressure from barbarians, the authorities had a correspondingly greater need for all the soldiers they could get to protect the Roman heartland. The province of Britain, for all its loyalty, was as far away from the Roman world’s most populous and wealthiest territory, in the eastern half of the Empire, as one could get.
In 383, the Western Roman Emperor, Magnus Maximus, began withdrawing Roman troops from western and northern Britain, and left local warlords in charge. This occurred at a time when the province was experiencing raids from Picts to the north, Scoti from Ireland, and Saxons from the continental mainland. The troop drawdown, which continued at a steady pace over subsequent years, led to a massive increase in the frequency and intensity of those raids.
By 410, the Romano-British had grown exasperated with the Roman authorities’ failure to protect Britain from attacks by increasingly bold barbarians. So that year, they expelled the officials of a Roman usurper, then wrote the emperor Honorius, seeking aid. Honorius, however, was hard pressed at the time by the Visigoths – who would soon sack Rome. His reply to the Romano-British, known as the Rescript of Honorius, told them he had no troops to spare, and advised them to see to their own defense.
Unfortunately for the locals, they proved incapable of uniting to govern themselves or organize a common defense. Of the barbarian raiders, the ones wreaking the most havoc and causing the most alarm were the Picts and Scoti, from Scotland and Ireland, respectively. So somebody had the idea of using one group of barbarians to fight off other barbarians, and a bargain was accordingly struck with some Saxon chieftains from the continental mainland.
It was an arrangement common in the Late Roman Empire and known as foederati, whereby barbarians were settled in imperial territory in exchange for military service. The Saxons were thus brought to Britain and settled in the eastern parts, in exchange for fighting off the Picts and Scoti. It did not work out well for the Romano-Britons, however. The Saxons, once they got themselves settled, liked their new land, and viewing their Briton hosts and patrons as soft weaklings who needed other men to fight for them, decided to help themselves to everything.