Gaelic warfare was the type of warfare practised by the Gaelic peoples, that is the Irish, Gaels in Scotland, and Manx, in the pre-modern period.
Irish warfare was for centuries centred on the Ceithearn (pronounced "Kern"), light skirmishing infantry who harried the enemy with missiles before charging. John Dymmok, serving under Elizabeth I's lord-lieutenant of Ireland, described the kerns as:
"... A kind of footman, slightly armed with a sword, a target [round shield] of wood, or a bow and sheaf of arrows with barbed heads, or else three darts, which they cast with a wonderful facility and nearness..."
For centuries the backbone of Gaelic Irish warfare were lightly armed foot soldiers, armed with a sword (claideamh), long dagger (scian),bow (bogha) and a set of javelins, or darts (ga). The introduction of the heavy Norse-Gaelic Gallowglass mercenaries brought long broadswords, similar to the Scottish claymore. Gaelic warfare was anything but static, as Irish soldiers frequently looted or bought the newest and most effective weaponry. By the time of the Tudor reconquest of Ireland, the Irish had adopted Continental "pike and shot" formations, consisting of pikemen mixed with musketeers and swordsmen. Indeed, from 1593 to 1601, the Gaelic Irish fought with the most up-to-date methods of warfare, including full reliance on firearms (see Nine Years' War).