Vortigern, however, was very uneasy, because Merlin had not only said that the struggle of the red and the white dragon represented his coming conflict with Constans's sons, but further added that he would suffer defeat.

This prediction was soon fulfilled.
Uther and his brother Pendragon landed in Britain with the army they had assembled, and Vortigern was burned in the castle he had just completed.
Shortly after this victory a war arose between the Britons under Uther and Pendragon, and the Saxons under Hengist.

Merlin, who had by this time become the prime minister and chief adviser of the British kings, predicted that they would win the victory, but that one would be slain.

This prediction was soon verified, and Uther, adding his brother's name to his own, remained sole king.

His first care was to bury his brother, and he implored Merlin to erect a suitable monument to his memory; so the enchanter conveyed great stones from Ireland to England in the course of a single night, and set them up at Stonehenge, where they can still be seen.
"How Merlin by his skill, and magic's wondrous might, From Ireland hither brought the Stonendge in a night." DRAYTON, _Polyolbion_.
[Sidenote: Round Table established by Merlin.] Proceeding now to Carduel (Carlisle), Merlin, who is represented as a great architect and wonder-worker, built Uther Pendragon a beautiful castle, and established the Round Table, in imitation of the one which Joseph of Arimathea had once instituted.