Cenn Fáelad mac Ailella (died 679) was an Irish scholar renowned for having his memory markedly improve after suffering a head wound in battle.
Had his brain of forgetting knocked out of him
so great were Ferchertne’s poetic powers that it was said that ‘the lakes and rivers drain before him when he satirises, and they rise up when he praises them’.
The Ogam Tract also gives a variety of some 100 variant or secret modes of writing ogham (92 in the Book of Ballymote), for example the "shield ogham" (ogam airenach, nr. 73).The training of the Gaelic poet or file involved learning one hundred and fifty varieties of ogham - fifty in each of the first three years of study, and it is clear that most of these are the varieties given in The Ogam Tract
Ogam tirda/Agricultural ogam
Ogam Uisceach/Water Ogam
Basogam/palm of hand ogam
Runogam na fian/Secret ogam of warriors
Ogam Bricrenn /Ogham of Bricrenn
Crad Cride Ecis/ Anguish of a Poet’s Heart:
Rothogam Roigni Roscadhaig/Wheel Ogham of Roigne Roscadach: The name Roigne Roscadach means ‘Choicest Rhetoric’ so again there is a link with poetry.
Fege Find/Fionn’s Window: This variety has the novelty of arranging the letters attractively in a series of circles
Ogam Lochlannach/Scandinavian Ogam
Cenn Fáelad fought at the battle of Magh Rath (Moira, County Down) in 636.
During the battle he received a life-threatening head wound, and was afterwards carried to the abbey of Tomregan, County Cavan to be healed in the house of its abbot, Saint Bricín. That this abbey was situated beside Magh Slécht where his father had been slain 16 years earlier may not be a coincidence. His family possibly had land there.
This house was situated "where the three streets meet between the houses of the three professors. And there were three schools in the place; a school of Latin learning, a school of Irish law and a school of Irish poetry. And everything that he would hear of the recitations of the three schools every day he would have by heart every night."
The effect of this trauma led him to create "a pattern of poetry to these matters and he wrote them on slates and tablets and set them in a vellum book." His verses were all composed in quatrains of numbered syllables with regular rhyme, and moderate use of alliteration, in contrast to a more archaic form that was still practised in the south of Ireland at the time
freedom of speech defended by columba at druim ceit