We begin this chronicle of slaughter and fighting men by discussing a battle in Wiltshire. It is a county which (fortunately) has seen few conflicts, despite its central position. In the spring or summer of 493 it was yet the location of Mons Badonicus or Mount Badon, described by the British historian Gildas, writing in 536. Even though this British victory halted Anglo- Saxon conquests for half a century, there has been no agreement on its date or location, despite a hazy belief in the former as between 490 and 520, and in the latter as in north Wiltshire, perhaps near Badbury, south of Swindon. Also unsure is whether the leader of the Britons was Arthur or Ambrosius Aurelianus. If we could be certain on these points, knowledge of Britain's history would progress considerably.

In what follows, six conclusions are offered: (a) Gildas wrote in 536, as argued in 2010 by David Woods of Cork; (b) the Siege of Mount Badon was 43 years earlier, and so in 493; (c) obscure and meaningless ‘Badon’ is a scribal error, and must be corrected to Braydon; (d) the siege was thus at Ringsbury, a hillfort above Braydon Forest, near Swindon; (e) Arthur, a North British warrior killed in 537, had no connection with the events in 493; and (f) the general who defeated a West Saxon army (surely marching on Cirencester) was instead the Ambrosius Aurelianus praised by Gildas. These conclusions have been in print for some years, but remain disputed. Hence this book.

An outline of earlier discussion allows understanding of both the problem and the solutions to it. Statements go back a long way. John Leland (d. 1552) quoted one from the twelfth- century chronicler Ralph of Diceto: ‘Gildas Britonum gesta flebili sermone descripsit anno domini DLXXXIII’ and thus ‘sub Mauricio imperatore’. Maurice was Emperor of Byzantium in 582– 602, which is far too late. If, however, we knew Ralph's source, it might be of great value; for emended DXXXVI would put Gildas in 536 and Badon in 493, as maintained here.

The difficulties are made clear by Philip Perry (1720– 1774), rector of the English College, Valladolid.