  We report the analysis of the rotational properties of our sample of Herbig
Ae/Be (HAeBe) and related stars for which we have obtained high-resolution
spectropolarimetric observations. Using the projected rotational velocities
measured at the surface of the stars, we have calculated the angular momentum
of the sample and plotted it as a function of age. We have then compared the
angular momentum and the vsini distributions of the magnetic to the
non-magnetic HAeBe stars. Finally we have predicted the vsini of the
non-magnetic, non-binary ("normal") stars in our sample when they reach the
ZAMS, and compared them to various catalogues of the vsini of main-sequence
stars. First, we observe that magnetic HAeBe stars are much slower rotators
than normal stars, indicating that they have been more efficiently braked than
the normal stars. In fact, the magnetic stars have already lost most of their
angular momentum, despite their young ages (lower than 1 Myr for some of them).
Secondly, our analysis suggests that the low mass (1.5 < M < 5 Msun) normal
HAeBe stars evolve with constant angular momentum towards the ZAMS, while the
high-mass normal HAeBe stars (M > 5 Msun) are losing angular momentum. We
propose that winds, which are expected to be stronger in massive stars, are at
the origin of this phenomenon.
