The Ormonius is a five-book heroic poem of nearly 4,000 hexameters on the military career of the Irish nobleman Thomas Butler, 10th Earl of Ormond (1531-1614). It was written by Ormond's fellow-Irishman, the medical doctor Dermot O'Meara, and was published in London by Thomas Snodham in 1615. Ormond was a powerful political leader in Ireland, loyal to the English crown. He was also a warlord, who took a prominent part in the suppression of numerous Irish rebellions and helped secure what historians refer to as the 'Tudor Conquest' of his homeland. It is almost exclusively around these military achievements that O'Meara constructed the poem, with each of its five books rehearsing the earl's exploits against such famous rebels as Sir Thomas Wyatt, Shane O'Neill, Sorley Boy McDonnell, James FitzMaurice Fitzgerald, the Earl of Desmond, and Hugh O'Neill, earl of Tyrone. Written at the end of the earl's life, Ormonius was intended to remind its audience of Ormond's central role in the conquest and the advancement of English royal power. Although writing the poem firmly within the classical didactic epic tradition, O'Meara utilised the framework of a contemporary Gaelic poetic form called the caithreim in its construction. Additionally, O'Meara drew upon a broad range of classical authors to augment and underpin his celebration of Ormond's life, from Vergil and Ovid to Silius Italicus and Claudian. The poem was most likely intended for King James VI & I. It was published too late, however, to influence the king's attitude towards the earl's family, which hardened after Ormond's death in 1614.