Uniquely among Irish Families, the MacEgans were distinguished for learning rather than military prowess. They became, over five centuries, Ireland’s most learned literary family and have left us an enormous body of medieval Irish and Latin writing. The great codices, the book of Duniry (Leabhar Braec), also called the Speckled Book of the MacEgans, the Book of Ballymote and the Book of the Dun Cow (Leabhar na hUidre) are associated with them. (The latter two texts can be found at the Ancient Texts Library.)

The Brehon (Judge) and Ollave (Professor) ranked among the highest in the Irish society, and the MacEgans were the outstanding hereditary holders of these offices. The Mac Egans were one of only seven Irish families to practice the ancient Brehon Law. Of these seven, five served just one ruling family, one served five senior lords, and members of the Mac Egan clan served as the chief advisors to all of the remaining thirteen lords and chieftains.

Because they were associated with the chieftains in all parts of the country their descendants are widespread. Among the O’Kennedys of Lower Ormand in North Tipperary they became particularly strong. There are a number of their castles still standing, and one of these, Redwood, where a celebrated law school once flourished, is restored and available to visit.

Throughout the annals there are numerous references to various members of the family noteworthy for their achievements as brehons and ollaves. For example, Michael O Cleirigh, principal author of Annals of the Four Masters from 1636, said Baothghalach Ruadh MacAodhagain was “the most learned Irishman that ever lived”. When the annals were compiled, O’Cleirigh sought an approbation from six of the most learned men in the Country for the work, the first being Flann MacAodhagain of Ballymacegan and Redwood Castle, while Baothghalach MacAodhagain, Bishop of Elphin was third on the list.

Later when the Normans adopted the Irish Language, law and custom, MacEgan brehons were retained by them as well. However, like other Irish Families who did not conform, they lost all when the English took over but preserved the educational tradition throughout the Penal Times. After Emancipation in 1829 many of the name followed their hereditary professions of teaching, law and medicine.

The Egan clan is descended from Cairbre Crom, chief of Hy Many in the 6th Century and has as its eponymous ancestor Aedhagan, who flourished in the 10th century, making the surname one of the oldest in Europe. It is derived from the root ‘aedh’ meaning ‘fire’ through its association with an ancient Irish fire deity and the diminutive ‘an’ hence ‘the little bright-eyed one’.

This evolved into the Gaelic name used by the Egan family in Ireland of Mac Aodhagáin, which means son of Aodh, a personal name usually Anglicized as Hugh. The “agáin” part is a frequent ending to Irish names and is often said to stem from Latin or Greek verbs meaning “born of”.

Many spelling variations of the name have been found in the archives, particularly when families attempted to translate the name from the Gaelic into English or vice versa. Egan occurs in many references, sometimes spelt Egan, Eagan, Keegan, MacEgan, Kegan, Keagan and Keagen and these changes in spelling frequently occurred, even between father and son.

Compounding the problem, church officials and scribes spelt the name as it sounded, and it was not uncommon to find a name spelt several different ways during the lifetime of the same person, when he or she was baptized, another when that person was married, and yet another appeared on the headstone. These variations continued into the migrations out of Ireland. In America, the spelling further evolved to Agin and Agins.

Just like “O,” the prefix Mc in front of a name, meaning `son of’ is popular in Irish names, although this doesn’t guarantee that the name is Irish. Officially, in both Ireland and Scotland, the abbreviation is Mac.

Roughly 14 of every 100,000 people in the US have an Egan-related surname.

The Coat of Arms for the surname Egan can be described in heraldic terms as follows:

That completes the meaning of the shield. The MANTLE can then be spread over the shield and draped from the helmet and serve as a protection “to repel the extremities of wet, cold, and heat, and to preserve the armour from rust.” The numerous cuts and slits suggest that it had been torn and hacked on the field of battle. The style or design of the mantling is up to the individual heraldic artist, and it is usually depicted in the main color and metal from the shield. The Esquire’s Helm, as depicted here, is generally shown silver, with a closed visor and facing to the dexter (its right). On top of the helmet is a Torse or wreath which was formed by two pieces of silk twisted together. Its purpose was to hold the crest and mantle on the Helm.

The Crest was worn on top of the helmet, and was usually made of wood, metal, or boiled leather. It provided the double advantage of easy identification and the addition of height to the wearer. The Crest for the surname Egan is shown atop the Mantle as a man in armor emerging from a tower holding a battle-axe. The Battle-Axe is common on crests as a symbol of authority and of the execution of military duty, thus denoting a warlike quality to its bearer. The Battle-Axe was a bearing introduced to heraldry as a token of the Crusades, which began shortly after the rise of heraldry itself.