Ethon was born as an illegitimate child to Dyron Blackgard and his mistress Luciya Allyrion. Dyron could not raise the child, fearing the scorning and humiliation he would receive from his family. Therefore, he refused to acknowledge him and Luciya was forced to take him with her to Godsgrace in Dorne, since the Dornishmen are far more lenient in siring bastards than the rest of the Seven Kingdoms.
Ethon was tutored by Daeron Allyrion in his youth. Daeron quickly became a father figure for the young Ethon. Ethon believed that his father was a farmer and his mother had died giving birth to him, completely oblivious to the fact that Luciya was his mother and that he is in fact a descendant from a powerful and ancient Great House.
Smooth, handsome, charming, witty and fully aware of it, Ethon carries himself with an air of supreme confidence (at times, pure arrogance) which is due in part to his exceptional combat skills and tutoring by Daeron Allyrion, who taught him the passions and lifestyles of a true Dornishman. Because of this, Ethon is always sure of success in whatever he does, regardless of whatever obstacles are in his way, and fears no consequences. On the rare occasions where he fails to get what he is after, Ethon usually displays remarkable temper control, often viewing such happenings with amusement and curiosity rather than frustration, likely a byproduct because of Daeron's influence, which also taught him the principles of honor and chivalry; it takes a great personal attack to actually enrage him.