The Laser Cannon was first used as the main direct-fire weapon of a Bolo in 2235 on the Mark X and only the Bolo Mark XIII followed this example (the Bolo Mark XI was a parallel development to the Mark X, retaining the then-traditional railgun while the Mark XII was a missile platform). The laser cannon was a development of the smaller weapons that had been used as infinite repeaters since 2209 but after less than a century as the Bolos' main gun, it was eclipsed by the Hellbore .