Intersecting families of permutations

Let S-n be the symmetric group on the set X = {1, 2, ..., n}. A subset S of S-n is intersecting if for any two permutations g and h in S, g(x) = h(x) for Some X E X (that is g and h agree on x). Deza and Frankl (J. Combin. Theory Ser. A 22 (1977) 352) proved that if S subset of or equal to S-n is intersecting then \S\ less than or equal to (n - 1)!. This bound is met by taking S to be a coset of a stabiliser of a point. We show that these are the only largest intersecting sets of permutations.