Here is a Trivial Pursuit question to begin with: What is the largest dinner of the year in London? The Lord Mayor's Banquet? No way: it's quality, not quantity in the Mansion House and Guildhall. The Professional Footballers' Association's self-congratulatory bash? The sub-postmasters' banquet (guest speaker Jim Fitzpatrick)?
No, it is none of those unmissable events. I'm quite sure the honour goes to the London Metal Exchange, which, year after year, feeds 1,500 in the Grosvenor House, plus another 1,000 or more in several satellite events elsewhere, connected up with video links. It's an odd experience if you're the speaker, not being able to see half your audience. (Last year, the problem was solved when the other rooms voted to switch off a long-winded invitee).
In spite of its culinary magnificence, the LME bash is one of the City's best-kept secrets. After the scandals of the late '90s (remember the Japanese Mr Five Percent, Sumitomo's Yasuo Hamanaka?) the market almost went under. It was rescued by two determined chairmen, Raj (now Lord) Bagri and Donald Brydon. As a result of their steely determination, Metals Week in the autumn brings hordes of well-heeled, copper-bottomed visitors to London, as the world's commodity gurus assemble to fix prices ... whoops, sorry - to debate future trends. This year's rumour was that one of the Chicago exchanges was about to make a run at the LME. I hope not, and that their merger plans preoccupy them by their lake for a long time to come. London's caterers couldn't stand the loss of business.