In colliding‐beam storage rings transverse and longitudinal beam halo is generated, or depleted, by the effect of head‐on and long‐range beam‐beam collisions. Measurements from several past and present lepton or hadron colliders are compared with simulations and analytical models, highlighting a few halo‐specific techniques. This overview concludes with an outlook on the future Large Hadron Collider (LHC), where long‐range beam‐beam collisions are the dominant perturbation of particle motion and beam‐beam compensation schemes appear a promising remedy.