In the early part of the period, central Europe is inhabited by various tribes, either pagan or newly Christian. By 1000, the region is the heartland of the Holy Roman Empire, a loose confederation of territory ruled by a Christian dynasty aspiring to the greatness of Roman and Byzantine imperial power. The shift affects patronage of the arts. Sixth- and seventh-century patrons commission portable metal objects and personal adornments that might aggrandize them anywhere; ninth- and tenth-century emperors seek to replicate the splendors of Christian Rome. They foster the building of stone churches and monasteries, the illumination of sumptuous books, and the casting of bronze sculptures in a revival of ancient technique.