In this period, the lands now known as England, Ireland, Scotland, and Wales are subdivided into smaller regions, each of which is governed by a territorial king. They are in constant contact and conflict with one another, frequently clashing over issues of land ownership and power. Often, rulers display their wealth and prominence by wearing splendid golden and jeweled brooches as marks of their status. During the fifth and sixth centuries, Christianity flourishes in Britain, especially in the monasteries, which become centers of learning and literacy. Indeed, a great deal of contemporary artistic production is linked to the Church, for example, elaborately decorated liturgical vessels for use in Mass, and fine illuminated manuscripts. There are also many surviving examples, especially in Ireland, Scotland, and Wales, of monumental sculptures, in particular, massive, carved stone crosses.