There is little documentary evidence about the nature of trade in Æthelberht's Kent. It is known that the kings of Kent had established royal control of trade by the late seventh century, but it is not known how early this control began. There is archaeological evidence suggesting that the royal influence predates any of the written sources. It has been suggested that one of Æthelberht's achievements was to take control of trade away from the aristocracy and to make it a royal monopoly. The continental trade provided Kent access to luxury goods which gave it an advantage in trading with the other Anglo-Saxon nations, and the revenue from trade was important in itself.