Imagine a man wearing a brightly-colored tunic with unbelievably baggy sleeves. His hair hangs in long bangs over his eyes. He carries a war dart- a kind of javelin- and wears a long dagger at his side. This startling figure prides himself on his extreme ferocity as a fighting man, and rumor has it that he makes a regular practice of taking his slain enemies' heads as trophies of his victory. He specializes in guerilla warfare- hitting the enemy hard and fast, and then escaping into the bogs and forests.

This man is a kern, an Irish foot soldier of the Middle Ages. Part of his fierce reputation is deliberately cultivated. It pays to have people scared of you if you fight for a living. Part of it simply anti-Gaelic prejudice on the part of English commentators. Part of it is due to the sheer spitefulness and violence of warfare on a frontier. When kern raid an English settlement, burn down houses, steal cattle and kill anyone who gets in the way, you can hardly expect the survivors to view them kindly. Of course, the English used the exact same tactics against the native Irish, and even employed kerns to do it, but people with a stake in an issue rarely consider it fairly or objectively.

The kern, in his own era, was seen as a figure of savage violence, a barbarian warrior. That picture would not be fair to the sophistication or complexity of the Gaelic culture from which he sprang. The easiest way to understand the kern is to consider what he was up against. The Gaelic chiefs who resisted conquest by the Anglo-Normans did not have the resources to field large armies of heavy cavalry backed by volleys of arrows. In order to fight back against those kinds of armies, they were obliged to use the resources they did have: rough terrain, suitable for highly mobile forces of lightly-armed raiders specializing in hit and run warfare. The kern was essentially just the product of a specific military situation.