A typical medieval Irish army included light infantry, heavy infantry and cavalry. The bulk of the army was made up of light infantry called "ceithern" (anglicized 'kern'). The ceithern wandered Ireland offering their services for hire and usually wielded swords, skenes (a kind of long knife), short spears, bows and shields. The cavalry was usually made up of a king or chieftain and his close relatives. They usually rode without saddles but wore armour and iron helmets and wielded swords, skenes and long spears or lances. One kind of Irish cavalry was the hobelar. After the Norman invasion there emerged a kind of heavy infantry called "gallóglaigh" (anglicized 'galloglass'). They were originally Scottish mercenaries who appeared in the 13th century, but by the 15th century most large "túatha" had their own hereditary force of Irish "gallóglaigh". Some Anglo-Norman lordships also began using "gallóglaigh" in imitation of the Irish. They usually wore mail and iron helmets and wielded sparth axes, claymores, and sometimes spears or lances. The "gallóglaigh" furnished the retreating plunderers with a "moving line of defence from which the horsemen could make short, sharp charges, and behind which they could retreat when pursued". As their armour made them less nimble, they were sometimes planted at strategic spots along the line of retreat. The kern, horsemen and "gallóglaigh" had lightly-armed servants to carry their weapons into battle.