Carolingian art comes from the Frankish Empire in the period of roughly 120 years from about 780 to 900 — during the reign of Charlemagne and his immediate heirs — popularly known as the Carolingian Renaissance. The art was produced by and for the court circle and a group of important monasteries under Imperial patronage; survivals from outside this charmed circle show a considerable drop in quality of workmanship and sophistication of design. The art was produced in several centres in what are now France, Germany, Austria, northern Italy and the Low Countries, and received considerable influence, via continental mission centres, from the Insular art of the British Isles, as well as a number of Byzantine artists who appear to have been resident in Carolingian centres.