Thibbeous the Unrepentant (approx. 759-April 4, 804 CE) was a Celtic warlord and chieftain who rose to prominence near modern day Galway, Republic of Ireland. Thibbeous united the pagan clans of Celtic people in their resistance to the spread of Roman Catholic Christianity into the western half of the island of Ireland. Sponsored by newly crowned “Holy Roman Emperor” Charlemagne and Pope Leo III, an expedition of 10,000 soldiers led by Louis the Pious was sent in 801 CE to Ireland in order to forcibly baptize and convert the pagans dwelling in the western half of the island. Thibbeous, chieftain of the Hernoricum tribe, was able to unite 11 different Celtic tribes under his leadership in order to repel the invading army. Thibbeous understood that his warriors were underequipped and disorganized compared to the invading Latins. In order to defeat the technically superior army Thibbeous lead his Cosantoiri, or “defenders” in Gaelic, in a guerrilla-style campaign. Utilizing the Celts familiarity with the landscape, Thibbeous used ambushes and skirmishes on carefully chosen ground to wear the Latins down slowly. Thibbeous won minor battles at Carran, Gort, Craughwell, and Spiddal but was unable to achieve a major victory that permanently ended the Latin invasion. On April 1st in the year 804, Thibbeous was captured by the Latin army during a pitched battle near the village of Athenry. Louis gave Thibbeous the opportunity to save his own life by publicly repenting of his sinful ways and converting to Christianity. Thibbeous refused to spurn his ancestral pagan beliefs and thus earned himself the enduring moniker “the Unrepentant” amongst the Celtic peoples. He was executed on the Fourth of April, 804 by beheading upon the command of Louis the Pious.