The "Scout Fleet" Assault on Babylon 5 occurred after the Second Shadow War and Sheridan's Campaign to liberate Earth. An alien race of unknown origin traversed through known space, attacking selected targets to test their defenses to ascertain whether or not it was worth conquest. In 2262, this species attacked Babylon 5 after encountering the Gaim sometime before, the latter of which were able to warn Babylon 5 in advance of the scout fleets arrival.