Gog and Magog
During the Middle Ages these two characters were thought to be nations that were confined behind an immense range of mountains, having been imprisoned there by Alexander the Great, who, when he conquered Britain, had used 6.000 iron and bronze workers to build a huge gate to hold them back. This is, of course, a complete fabrication, for Alexander the Great never landed anywhere on the British Isles.
In the Arthurian tales it seems that they escaped their confinement and attacked Arthur, but the latter was helped by the giant Gargantua, and Gog and Magog were overcome. They were then said to have been chained to a palace on the site of London's Guildhall.
This pair are perhaps none other than the giants of the same name that appear in the Bible (Ezekiel 38, passim: Revelation 20:8).
Not all tales make Gog and Magog separate giants, referring instead to a single gigantic character known as Gogmagog. It is said that he led twenty others against Brutus at Totnes, Devon, but was engaged in single combat by Corineus, Brutus' ally, who defeated him and chained to a palace that once stood on the site of the Guildhall in London, the palace possibly being the one established by Brutus in his capital of Troia Nova. He was thrown over the cliffs to his death, though some accounts place this battle at Plymouth.
This legendary giant is still remembered today at Cambridgeshire, where his name is given to a range of low-lying hills to the west of Cambridge.
Goemagot | The Legend of King Arthur
Gogmagog | Myths and Legends