retreated from Britain, various kingdoms sprouted up to the south of Scotland. One of these, Northumbria, soon expanded into the north as far as the Kingdom of Strathclyde. Thus, it controlled the southern parts of what is now Scotland, and the bronze sceat coins of the Northumbrian Kings circulated freely in what is now Scotland. This coin was issued from 837–854. Anglo-Saxon coins were minted in Northumberland; however, due to the extensive trade routes of the Vikings, sceat coins were also minted in Frisia and Jutland during Anglo-Saxon times and coins of this period indicate the extent of Scottish trade not only with Northumberland but also with continental Europe. Norsemen also introduced some form of coinage, and coins from as far away as Byzantium and the Arabic countries have been found in sites in Scandinavia, including Norway which had strong links with Scotland in the early Middle Ages. Scottish Penny (–1602) The first king of Scots to produce his own coinage was David I (). In 1136 he captured Carlisle, including its English mint and nearby silver mines from Stephen, King of England. He struck silver pennies, which were similar to those Stephen struck for England, at Carlisle, Edinburgh, St Andrews, Roxburgh and Berwick. For the next two centuries, the continued use of a profile, as opposed to the facing portrait, was about all that distinguished Scottish coins from their English counterparts. In particular, the reverse types of Scottish coins followed the English Tealby, short cross, and long cross designs. Moreover, Scottish coins followed English weight standards, allowing the two coinages to circulate alongside one another. David II of Scotland ended the parity between Scottish and English coins, resulting in an English proclamation banning the lower quality Scottish coins from their country in 1356. Robert III of Scotland continued to devalue Scottish coins, making them worth one-half of their English counterparts by 1392. He also replaced the profile bust on the obverse of Scottish coins with a facing head, which made his coins much easier to confuse with the more valuable English issues. David II's attempt to introduce gold coins to Scotland by copying the English noble was a failure but Robert III successfully introduced the gold lion, which showed St. Andrew crucified on his saltire-shaped cross. Under James III of Scotland English influence of Scottish coinage gave way to Burgundian models, with both his gold rider and silver plack.