Gildas was the first local writer to record his feelings after the Roman world collapsed. Born around 500 AD in what was to become north Wales, he grew up to become a Celtic monk who felt the turmoil of the years following Roman withdrawal. He also composed a "Rule" for monastic life which clearly shows he was from that side of the street. The Anglo-Saxons had arrived, and Gildas was trying to make heads or tails what what was happening around him. He states in his opening that his premise is: "...for it is my present purpose to relate the deeds of an indolent and slothful race,...". He states: "..for, alas! the subject of my complaint is the general destruction of every thing that is good, and the general growth of evil throughout the land..."
In section II, which he calls "THE HISTORY", item 23, he records the following:
"Then all the councillors, together with that proud tyrant Gurthrigern [Vortigern]
,the British king, were so blinded, that, as a protection to their country, they sealed its doom by inviting in among them (like wolves into the sheep-fold), the fierce and impious Saxons, a race hateful both to God and men, to repel the invasions of the northern nations. Nothing was ever so pernicious to our country, nothing was ever ever so unlucky."
Thus begins the history of our great grandfather Vortigern!
[The reference for these quotes is: Medieval Sourcebook (Gildas (c.504-570) Works (complete).