Battle of Guoloph The Battle of Guoloph took place in the year 439 ( 437 according to some sources ) at what is now Nether Wallop , 15 kilometers southeast of Amesbury , in the district of Test Valley , northeastern Hampshire . The battle pitted a Britonnic alliance against invading Jutes and Saxons . The Britons were victorious . Context . In his book , " Historia Brittonum " , Nennius affirms that " The reign of Vortigern , and the fight between Vitalinus and Ambrosius in Guoloppum , the Battle of Guoloph , are separated by twelve years " . In the 12th century A . D . ( largely fictitious ) pseudo - history written by Geoffrey of Monmouth - the Historia Regum Britanniae - Ambrosius Aurelianus ( " Emyrs Wledig " , " the imperator " ) is considered the son of the emperor Constantine . Geoffrey of Monmouth states that while Ambrosius was a child , his entire family was assassinated with only him and his brother Uthyr Pendragon making their escape via a canal at the court of their cousin , Budic I of Brittany . This attack was allegedly perpetrated by Vortigern , governor of the city of Dubris , one of the most important ports in the kingdom . Vortigern had formed a pact with the powerful Jute kings , Hengist and Horsa . Years later , Ambrosius returned to Great Britain , disembarking at Totnes ( Devon ) , a reunion of the monarchs of all the kingdoms of the south with the purpose of forging alliances and solving collective problems . It was there that he was able to convince the Romano - British leaders of the Jute menace and of their alliance between Vortigern . The Battle . The Romano - British leaders formed a coalition to confront the Jutes and the battle occurred in the vicinity of Guoloph where after bitter fighting , they defeated Vitalinus ( Most likely Vortigern or one of his commanders , " cp . " Nennius records " Vitalinus " as Vortigern ' s grandfather ) . Aftermath . The fight between Ambrosius Aurelianus and Vortigern lasted for the better part of both their lives . The pro - Saxon agenda of Vortigern eventually led to his fall and probably around the latter part of the 450 ' s , the Britano - Romans finally united under the Banner of Ambrosius , besieging Vortigern at his fortress at Caer - Guorthigirn ( Little Doward , Herefordshire ) which they burned to the ground killing everyone inside . Archaeology and Legacy . In the parish of Nether Wallop , northeast of the town of the same name , there is a fortress on the hill of Danebury dated to the Iron Age where a multitude of excavations have taken place between 1968 to 1988 . There is no evidence of its occupation during the Roman period , but there is ample evidence of its fortification in Sub - Roman Britain . The perimeter of the defensive works has been lost to the years , but the trench work is still discernible , archaeologists having found ceramics from the 5th and 6th centuries . This allows the fortifications to be dated contemporarily to the battle between Vitalinus and Ambrosius . Some historians maintain that Ambrosius himself was responsible for the refortification of Danebury prior to the Battle of Wallop in 437 , but there is no hard archaeological evidence to support these theories . It is probably that the battle actually occurred further to the south where the enemy would have been able to have taken up a strategic position that the Celtic tradition recalls as Cad Hill ( now Chattis Hill ) on the border of Nether Wallop and Broughton . The accounts of " Historia Britonum " place the Battle of Guoloph as having occurred in 439 , some forty to fifty years before the historian Gildas places the battles commanded by Ambrosio Auireliano . This leads historians to debate the accuracy of the first accounts of these conflicts or that they refer to different persons . Others still identify Ambrosius as King Arthur or as one of the historical figures Arthur ' s achievements are based on .