  UBVI and Ha photometry is presented for 17319 stars in vicinity of the young
double cluster h & chi Persei. Our photometry extends over a 37arcmin x 1arcdeg
field centered on the association. We construct reddening contours within the
imaged field. We find that the two clusters share a common distance modulus of
11.75$\pm$0.05 and ages of log age(yr) = 7.1$\pm$0.1. From the V-Ha colour, a
measure of the Ha emission strength, we conduct a survey for emission line
objects within the association. We detect a sample of 33 Be stars, 8 of which
are new detections. We present a scenario of evolutionary enhancement of the Be
phenomenon to account for the peak in Be fraction towards the top of the
main-sequence in the population of h & chi Persei and similar young clusters.
