 More recent scholars however have posited that the formation of the themes did not constitute a radical break with the past, but rather a logical extension of pre-existing, 6th-century trends, and that its direct social impact was minimal.What is clear is that at some point in the mid-7th century, probably in the late 630s and 640s, the Empire's field armies were withdrawn to Anatolia, the last major contiguous territory remaining to the Empire, and assigned to the districts that became known as the themes.Territorially, each of the new themes encompassed several of the older provinces, and with a few exceptions, seems to have followed the old provincial boundaries.