In the first decade of the 5th century AD, in the years before Alaric marched his Visigoth horde into Rome and sacked the city, Britannia was, albeit temporarily, at peace. In the four hundred years since the first Roman invasion, tyrannical military force had largely tamed the native Celtic population, bringing classical education, economic stability, and ultimately, even Christianity to the Islands, following its adoption as the official religion of the Empire in 313 AD.