Two questions on the Arsenal website say everything you need to know to explain why more than 7,000 Welshmen will be travelling to London on Saturday giggling themselves silly.
"Which year did Arsenal first play in a FA Cup final?" Answer: 1927. "And what was so unusual about the team they lost to?" Answer: It was Cardiff City.
Seventy-nine years on it is possible to accept that pithy explanation and move right on. After all, in the illusory "it's always been like this" world of modern football, what could be more unusual than a) Cardiff beating Arsenal; and b) doing so in an FA Cup final? But as anyone who has been within 100 yards of a Bluebird since this most resonant of third-round fixtures was drawn will confirm, "what was so unusual" was not Cardiff's status but that little matter of their nationality.
For this was the first and, so far, only time that the FA Cup had been taken out of England. (Cardiff, and indeed Swansea and Wrexham fans, insist on the "so far" in this statement.) It is small wonder, then, that the proud folk of Cardiff need no excuse to evoke the images of that year after the General Strike, although they are as pleased as punch - as one of their most famous fans, Neil Kinnock, might say - to be given the chance to do exactly that with their first visit to Highbury in more than two decades.
Alas, Ninian Park is strangely reluctant to crow about the club's day in history - the only perceivable evidence to the anoraked eye are the triangular corner flags that FA Cup winners alone are allowed to use - although the rest of the city is not nearly so bashful. For instance, take a short walk west from the capital's centre and you will come across "The 1927 Cafe" and any non-themed public house worthy of its backstreet will have a photo, a commemorative plaque or the like of 23 April, 1927.
The matchball itself takes pride of place in the Welsh Sports Hall of Fame collection in the Welsh Museum at St Fagans, although the last member of the triumphant team, "young Ernie Curtis", sadly took the remaining first-hand memories with him when he died around 10 years ago. Nevertheless, a few old boys who were there - and any number who weren't - still have their tales to tell and nowhere are they recounted more authentically, or more eloquently, than at Glamorganshire Golf Club every week when David Morgan and his lifelong friend, Edgar Rushton, meet to play and reminisce. Both are 94 years of age and both, incredibly, were at Wembley that historic afternoon.
"People forget this, thinking it was some outrageous one-off, but two years before Cardiff had lost out in the final to Sheffield United," said Morgan, from his seaside home a few miles from his beloved Ninian Park. "I was staying with friends near Fishguard for that match, and in those days there was no radio, no telephone in the house, no way of finding out what was happening. We cycled to the Post Office two miles away to find the score. I must tell you, it was a bloody long journey back.
"Fred Keenor, our captain, pledged that day we would go back up there and this time win and when we got to the final again I persuaded my father to take me. We went up to London by train and booked in at our hotel, the Cecil on the Strand, which was long ago demolished, and skipped up to Wembley. It was a dour affair, to be honest, with a really nervy atmosphere, but when [Hughie] Ferguson scored the whole crowd leapt up. Well, the whole crowd, that is, apart from one man sitting in front of us. My father had inadvertently pushed the chap's bowler hat and it had lodged in front of his eyes. He couldn't see a thing. But then I'm not sure he wanted to. He was an Arsenal supporter who'd somehow come to sit in the wrong place.
"I'm telling you those last 20 minutes were the longest in the history of mankind. I can't explain the emotions when we won and what it was like to see the King hand over the Cup to a Welsh team, with Churchill and Lloyd George behind him. Even though I was I only 16 I realised there was something deeply symbolic in that moment.
"That night, to celebrate, we had supper at Simpsons on the Strand. My father called the waiter over, gestured to his friend Willie and whispered, 'This here is Billy Hardy, the Cardiff half-back, and he's just won the Cup.' The waiter was terribly impressed, congratulated Willie on his success and ripped up the bill.
"It wasn't true, of course, but then it was a special occasion, as confirmed by the 250,000 who were on the streets of Cardiff the next day to see the open-topped bus parade. What a brilliant, brilliant experience. Do you know after that they had to rename the 'English Cup', the 'FA Cup' and that this was the first time 'Abide With Me' was sung before the Cup final?"
Indeed, it was a day of firsts and not simply the obvious one. They were not as privileged as David and Edgar, of course, but the many thousands who lined up outside the City Hall were still blessed to hear the live commentary on the loudspeakers hung from the trees as the world's most famous football competition had never been broadcast before.
As a gimmick, or as the Radio Times put it "to help the listeners follow the play more clearly", they printed a plan of the pitch divided up into numbered squares. The commentators would refer to the ball being "booted up to square eight", "headed into square six" and so on and this is undoubtedly where the expression "back to square one" originated.
Tell a Cardiffian this and they will laugh with the irony of it all. "English football going back to square at one, eh?" It wasn't, of course, and Cardiff's joy was all too shortlived as the club slipped into a depression they have yet to climb out of, whatever Sam Hammam may claim.
As the Bluebirds survey a debt of at least £30m, peer down a squad so severely stretched it is astounding that Dave Jones has achieved a top-half placing in the Championship and as they wait, and wait, and wait for the promised new stadium their chairman maintains will be the making of Cardiff City, there are still, at least, the legends of '27 to wax lyrical about. And none has burnt so many candles in the intervening years as the fate which befell the poor Arsenal goalkeeper that day.
Dan Lewis was a Welsh international from the Bluebirds' catchment area of the Rhondda Valleys who had worked his way to Highbury. After 73 minutes, Ferguson unleashed a shot that Lewis seemingly had covered. But somehow the ball escaped from his grasp, rolled over his forearm and bounced into the goal. The resulting English whispers were inevitable, although Lewis claimed until his death it was the greasy new shirt that was to blame.
To this very day, the story goes, every new goalkeeper's shirt at Arsenal is washed before it is worn. What Cardiff City would do for Jens Lehmann to forget that tradition this weekend.
How the world looked in 1927
20-21 May: First solo non-stop transatlantic flight, New York to Paris, by Charles Lindbergh.
World population reaches two billion. Now six billion.
1,000 Britons a week die in influenza epidemic.
Prime Minister is Stanley Baldwin (Conservative).
Ford Motor Company ceases production of Model T.
The Academy of Motion Picture Arts and Sciences, which awards the Oscars, is founded.
"Ol' Man River" (Jerome Kern & Oscar Hammerstein II); "S'Wonderful" (George & Ira Gershwin).
First demonstration of television before live audience.
First transatlantic telephone call between New York City and London is made in January.
First live cricket commentary broadcast by the BBC. For Essex against New Zealand at Leyton, the Rev F H Gillingham gives a 10-minute introduction and then speaks for five minutes every hour on the hour between 3pm and 6pm.Reuse content