When, however, the Saxons had established themselves in sufficient numbers, they had their headquarters in Exeter; but there they did not amalgamate with the natives. The Saxon town was quite apart from that occupied by the Britons, or West Welsh, as they called our Dumnonians. That part of Exeter which contains dedications to Celtic saints was the British town, as was also Heavitree,[8] with its daughter churches of S. Sidwell and S. David; but the Saxons occupied where now stands the Cathedral; and each settlement was governed by its own laws. It was not till 823 that Egbert, by a decisive battle at Gavulford (_Gafl_ a holdfast, and _ffordd_ a road), established Saxon supremacy. He apparently drove the Devonshire Celts back along the Old Street, or Roman road, past Okehampton, till they made a stand at Coombow (_Cwm-bod_ = the habitation in a combe). There the hills close in on the road on both sides, and the way branched to Lydford. Commanding both roads is Galford Down; there the Britons threw up formidable entrenchments, or, what is more probable, occupied an earlier camp that remains intact to the present day. Here they made a desperate stand, and were defeated; after which the king, Egbert, cast up a _burgh_ beyond the old _dun_, which gives its second name to the place, Burleigh, or Burgh-legh. The last relics of the independence of the Dumnonian kingdom disappeared after Athelstan's visit in 926 and 928. A relic of this visit may be seen in Rougemont Castle, Exeter, where the Anglo-Saxon work--notably some herring-bone masonry, and windows rudely fashioned without arches--remains. [8] Names of places, as Heavitree, Langtree, Plymtree, take the "tree" from the Welsh "tref," a farm or habitation. Heavitree is Tre-hafod, the summer farm.