Our fuller sources for Ireland of the same period suggest that there would have been filidh, who acted as poets, musicians and historians, often attached to the court of a lord or king, and passed on their knowledge and culture in Gaelic to the next generation. In the Northern Isles the Norse language brought by Scandinavian occupiers and settlers evolved into the local Norn, which lingered until the end of the eighteenth century and Norse may also have survived as a spoken language until the sixteenth century in the Outer Hebrides. French, Flemish and particularly English became the main language of Scottish burghs, most of which were located in the south and east, an area to which Anglian settlers had already brought a form of Old English. In the later part of the twelfth century, the writer Adam of Dryburgh described lowland Lothian as "the Land of the English in the Kingdom of the Scots". At least from the accession of David I, Gaelic ceased to be the main language of the royal court and was probably replaced by French, as evidenced by reports from contemporary chronicles, literature and translations of administrative documents into the French language. After this "de-gaelicisation" of the Scottish court, a less highly regarded order of bards took over the functions of the filidh and they would continue to act in a similar role in the Highlands and Islands into the eighteenth century. They often trained in bardic schools, of which a few, like the one run by the MacMhuirich dynasty, who were bards to the Lord of the Isles, existed in Scotland and a larger number in Ireland, until they were suppressed from the seventeenth century. Members of bardic schools were trained in the complex rules and forms of Gaelic poetry. Much of their work was never written down and what survives was only recorded from the sixteenth century. In the late Middle Ages, Middle Scots, often simply called English, became the dominant language of the country. It was derived largely from Old English, with the addition of elements from Gaelic and French. Although resembling the language spoken in northern England, it became a distinct dialect from the late fourteenth century onwards. It began to be adopted by the ruling elite as they gradually abandoned French. By the fifteenth century it was the language of government, with acts of parliament, council records and treasurer's accounts