I’m told Gildas suggests a date in the first half of the first century (I haven’t read him). That seems extraordinarily unlikely, and anyway Gildas was unpleasantly anti-English, and so patently doesn’t deserve to be believed.
“Meanwhile these islands, stiff with cold and frost, and in a
distant region of the world, remote from the visible sun, received
the beams of light, that is, the holy precepts of Christ, the true
Sun, showing to the whole world his splendour, not only from the
temporal firmament, but from the height of heaven, which surpasses
every thing temporal, at the latter part, as we know, of the reign
of Tiberius Caesar, by whom his religion was propagated without
impediment, and death threatened to those who interfered with its
professors”.
Thus GIldas. Which is the standard for those folks, who, following the
legendarium of such as (classically) L. S. Lewis/ST. JOSEPH OF ARIMATHEA AT GLASTONBURY, or, (contemporary) R.C. Harvey/TO THE ISLES AFAR OFF, will take the mid-30s as the point at which the Faith came to the Isles (after the Feet, in Ancient Times). And, of course, many other far-reaching and unlikely things are supposed and adduced. I got books.
Reason I got books was my wife’s (bibliophile, to be sure) passing and past interest in the Matter of Britain. Which led, naturally, to Glastonbury and thorn bushes, and down weirder and weirder unhinged corridors of legend. Subject comes up here, from time to time.
GKC