Ambrosius Aurelianus

Ambrosius Aurelianus (Welsh: Emrys Wledig; Anglicised as Ambrose Aurelian and called Aurelius Ambrosius in the Historia Regum Britanniae and elsewhere), was a war leader of the Romano-British who won an important battle against the Anglo-Saxons in the 5th century, according to Gildas. He also appeared independently in the legends of the Britons, beginning with the 9th-century Historia Brittonum. Eventually he was transformed into the uncle of King Arthur, the brother of Arthur's father Uther Pendragon, and predeceases them both.

Due to Gildas' description of him, Ambrosius is one of the figures called the Last of the Romans.

Ambrosius Aurelianus is one of the few people that Gildas identifies by name in his sermon De Excidio et Conquestu Britanniae, and the only one named from the 5th century.De Excidio is considered the oldest extant British document about the so-called Arthurian period of Sub-Roman Britain. Following the destructive assault of the Saxons, the survivors gather together under the leadership of Ambrosius, who is described as:

Some basic information on Ambrosius can be deduced from the brief passage: Ambrosius was possibly of high birth and very likely a Christian (Gildas says that he won his battles "with God's help"). Ambrosius' parents were slain by the Saxons and he was among the few survivors of their initial invasion.

According to Gildas, Ambrosius organised the survivors into an armed force and achieved the first military victory over the Saxon invaders. However, this victory was not decisive: "Sometimes the Saxons and sometimes the citizens [meaning the Romano-British inhabitants] were victorious."

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