That is interesting and I didn't know about the
York Run as an earlier thing than the 'birth of Audax' in Italy. Remarkably similar time limits (per distance) too. (More challenging of course back then, on boneshakers and unmade roads.)
But none of that really addresses the 'Easter' bit in the topic. AUK's York Arrows are an emulation of ACP's
Flèche Vélocio, named for an old geezer with a soup-strainer moustache who set the ground rules for randonneuring along with 'seven commandments' which ran along the lines of "eat before you're hungry, drink before you're thirsty", "always be polite to others" and other obvious stuff like that.
This event was created in 1947 and particpants converge on a nominated location in Provence which is different every year, but typically it's a 'down the Rhone valley with the wind on your back then left near the bottom' sort of thing.
That ties in with FFCT's
Pâques en Provence, a big Easter cyclists' gathering, and I don't know when that started but I would imagine maybe 1920s.
The reason AUK started their own version was to enable UK cyclists to qualify for ACPs
Brevet 5000 (which I think they now call Randonneur 5000) which required a
Flèche Vélocio as one of the qualifying rides. In the early days of AUK a lot of AUKs rode
Flèche Vélocio, but obviously it did present difficulties and AUK's Secretary negotiated a special dispensation from ACP to emulate it as a 'York Arrow' in the UK and be able to count that instead of a
Flèche Vélocio. We wanted to tie it in with the
York Rally (June - as was) - similar to the
Pâques en Provence tie-in - but ACP wouldn't have that, and insisted the event be run at Easter when the weather was less likely to be benign, to make it more like the French event (Easter in N.England, Easter in S.France, yeah, right
). So we ended up with the 2 versions, Easter and Summer Arrows, with only the Easter version being recognised by ACP.