"England's difficulty, we used to say, is Ireland's opportunity. This is their chance to pay off racial scores, and to have some blood-letting as sport, and to make a bit of money in ransoms."
— Terence Hanbury White, The Queen of Air and Darkness
Mediaeval Ireland, for all purposes, remained poor and backward, for the reasons that no one single unified government existed to keep things in check. As such, however, one man's desperation is another man's opportunity, and so the Welsh and Scots have benefitted especially from the migration of native Irish, seeking glory and (more importantly) riches through service on the battlefield.
As can be expected, Hibernians are not effective units, and are one step near from being little better than the Asian-style suicide soldiers, due to their deficiency in armour. They, however, have a limited ranged attack that makes them useful against enemy foot archers, perhaps slightly moreso than shield bearers usually are. However, as can be expected, do not expect to think of fielding them except in large numbers against enemy melee units, and always be wary of heavy cavalry and siege weapons, which can make short work of them. Note that has they are armed with javelins, they do not have the anti-spear or anti-building bonus which most medium infantry normally have.
A renegade version of the Hibernian, the kerne, wander Europe as journeymen and will sell their service to the highest bidders. These units are recruitable as single-unit infantry only, and unlike normal Hibernians are recruitable only in the Castle Age.
- The Quick and the Dead — Due to their deficiency in armour but fast training time and quick speed, Hibernians are best used either in large numbers against enemy melee units, or in small groups away from them.
- The Downtrodden — Hibernians are weak against cavalry and siege weapons — keep them at bay from your troops at all costs!
- Kerne — A mercenary version of this unit is available in the Castle Age to selected factions, but costs entirely of wealth.
As Ireland slowly fell to the Anglo-Norman colonists who were now increasing their stranglehold over the island, so too did the tactics and the training of the locals change to meet the new challenges posed by the newcomers. By the Hundred Years' War in France, we hear of Irish ceithernn being arrayed in professional bands of men armed with more conventional weapons, and even on horseback.
- Byzantine Military, Akritai - Byzantine Border Troops