Back in 1937 the world's first science fiction convention was held in Leed England. About 20 people gathered for the days lectures and presentations. Among the several notables was a much younger Arthur C. Clark.
Strangely the title for first convention is contested by a convention held in America in 1936. Though in reading this seems more of a gathering friends than a convention with a program and schedule in it. I think for this Troll's part I'll have to give the title to Leeds.
But that aside, its really something to thing of the genre in its early days, and these were way before it became main stream.
Of equal interest is the program guide. Not only is it short and simple and to the point, its reveals a convention that is actually structured much like an academic conference. Much of it is about the creation of the Science Fiction Association. See playbill here.
Its also interesting to note how many people in that picture are smoking.
Read the full story of the con here!