The Anglo-Saxon period extended from c. 500 to 1066. During this time, England was largely occupied and ruled by Germanic peoples, primarily the Angles and the Saxons. Prior to the Viking incursions of the ninth century, the culture of England interacted closely with that of Celtic Britain and Ireland. The art produced during the four centuries from c. 550 to 900 is often termed Insular, reflecting this interaction among the peoples inhabiting the regions that we know as the British Isles and Ireland. With reference to Illumination, the term Anglo-Saxon is often reserved for the period after 900. During the tenth century, two major Anglo-Saxon painting styles developed, largely under the influence of Insular and Carolingian models. The first, or Winchester, style is so named because certain of its key examples, such as the Benedictional of Saint Ethelwold, were probably made at Winchester, even though the style was diffused throughout the region. It is characterized by an opulent manner of painting, with rich colours and gilding (unless executed in a tinted or outline drawing style), a naturalistic figure style, fluttering, decorative drapery, and a heavy acanthus-like ornament. This style exhibits the influence of Carolingian art, specifically the Court School of Charlemagne, the School of Metz, and the Franco-Saxon School (which employed interlace motifs ultimately of Insular inspiration), and is also indebted to Byzantine art. The second major style, the Utrecht style, was inspired by the Utrecht Psalter, an important Carolingian manuscript that featured an agitated, sketchy, and illusionistic form of outline drawing adopted from classical painting technique. During the first half of the eleventh century, the Winchester and Utrecht styles began to fuse. Scandinavian art also exerted a limited influence during the Anglo-Saxon period. Anglo-Saxon art continued to exchange influences with art on the Continent and made a significant contribution to the formation of Romanesque art. It also developed a number of sophisticated iconographies, based on interpretative, exegetical literature (important themes include the Trinity, the Crucifixion, the Virgin, the evangelists, and David).