foundation · 445 · Armagh
Patrick left the Confession and the Letter to the Soldiers of Coroticus, and they are the earliest writing to survive from Ireland or Britain by a named author. Everything else — the date of his mission, the shamrock, the snakes, the contest at Tara, even the year of his death — comes from lives written three centuries and more later, when Armagh had an interest in his primacy. His own pages contain no dates and no useful place names. What they do contain is a voice: a Roman Briton taken by raiders at sixteen and made a herdsman for six years, who escaped, went home, and then went back to the people who had enslaved him. He writes as a man under attack by his own superiors, defending a mission they thought irregular, and he calls himself unlearned so often that it reads as a wound rather than a formula. The Letter is fiercer and rarer still: a bishop excommunicating a British warlord for slaughtering and enslaving his newly baptized converts, which is one of the earliest Christian denunciations of slave-raiding by name. This dataset dates the see of Armagh to 445 by convention and marks that the date is convention, not evidence.
What can actually be known about Patrick?
Two documents he wrote himself, and almost nothing else — which is the opposite of the impression he leaves.