<P> With the final legalization of Christianity, the existing styles of Christian art continued to develop, and take on a more monumental and iconic character . Before long very large Christian churches began to be constructed, and the majority of the rich elite adapted Christianity, and public and elite Christian art became grander to suit the new spaces and clients . </P> <P> Although borrowings of motifs such as the Virgin and Child from pagan religious art had been pointed out as far back as the Protestant Reformation, when John Calvin and his followers gleefully used them as a stick with which to beat all Christian art, the belief of André Grabar, Andreas Alföldi, Ernst Kantorowicz and other early 20th - century art historians that Roman Imperial imagery was a much more significant influence "has become universally accepted". A book by Thomas F. Mathews in 1994 attempted to overturn this thesis, very largely denying influence from Imperial iconography in favour of a range of other secular and religious influence, but was roughly handled by academic reviewers . </P> <P> More complex and expensive works are seen, as the wealthy gradually converted, and more theological complexity appears, as Christianity became subject to acrimonious doctrinal disputes . At the same time a very different type of art is found in the new public churches that were now being constructed . Somewhat by accident, the best group of survivals of these is from Rome where, together with Constantinople and Jesusalem, they were presumably at their most magnificent . Mosaic now becomes important; fortunately this survives far better than fresco, although it is vulnerable to well - meaning restoration and repair . It seems to have been an innovation of early Christian churches to put mosaics on the wall and use them for sacred subjects; previously the technique had essentially been used for floors and walls in gardens . By the end of the period the style of gold background had developed that continued to characterize Byzantine images, and many Early Medieval Western ones . </P> <P> With more space, narrative images containing many people develop in churches, and also begin to be seen in later catacomb paintings . Continuous rows of biblical scenes appear (rather high up) along the side walls of churches . The best - preserved 5th - century examples are the set of Old Testament scenes along the nave walls of Santa Maria Maggiore in Rome . These can be compared to the paintings of Dura - Europos, and probably also derive from a lost tradition of both Jewish and Christian illustrated manuscripts, as well as more general Roman precedents . The large apses contain images in an iconic style, which gradually developed to centre on a large figure, or later just the bust, of Christ, or later of the Virgin Mary . The earliest apses show a range of compositions that are new symbolic images of the Christian life and the Church . </P>

What is the main difference between the floor plans during the early christian and byzantine time
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