The conquest of Scotland proved a far more difficult matter than that of Wales. The early history of the kingdom of Scotland is a complicated one. When the Angles and Saxons landed in Britain, a great part of the mountainous region north of the Firth of Forth was inhabited by a Celtic tribe, the Picts. There was, however, on the west coast a little kingdom of the Irish Celts, who were then called Scots. By the opening of the tenth century the Picts had accepted the king of the Scots as their ruler, and the annalists begin to refer to the highland region as the land of the Scots. As time went on the English kings found it to their advantage to grant to the Scottish rulers certain border districts, including the Lowlands, between the river Tweed and the Firth of Forth. This region was English in race and speech, while the Celts in the Highlands spoke, and still speak, Gaelic. [Sidenote: Character of the inhabitants of the Lowlands.] It was very important in the history of Scotland that its kings chose to dwell in the Lowlands rather than in the Highlands, and made Edinburgh, with its fortress, their chief town. With the coming of William the Conqueror many Englishmen, and also a number of discontented Norman nobles, fled across the border to the Lowlands of Scotland, and founded some of the great families, like those of Balliol and Bruce, who later fought for Scottish liberty. During the twelfth and thirteenth centuries the country, especially in the south, developed rapidly under the influence of the neighboring Anglo-Norman civilization, and the towns increased in size and importance. [Sidenote: Edward intervenes in Scotch affairs.] [Sidenote: Alliance between Scotland and France.] It was not until the time of Edward I that the long series of troubles between England and Scotland began. The death of the last representative of the old line of Scotch kings in 1290 was followed by the appearance of a number of claimants to the crown. In order to avoid civil war, Edward was asked to decide who should be king. He agreed to make the decision on condition that the one whom he selected should hold Scotland as a fief from the English king. This arrangement was adopted, and the crown was given to Robert Balliol. But Edward unwisely made demands upon the Scots which aroused their anger, and their king renounced his homage to the king of England. The Scotch, moreover, formed an alliance with Edward's enemy, Philip the Fair of France; thenceforth, in all the difficulties between England and France, the English kings had always to reckon with the disaffected Scotch, who were glad to aid England's enemies. [Sidenote: Edward attempts to incorporate Scotland with England.]