The person with the most songs written about them [ that I could find ] is Kevin Barry which has 16 that I know of. Kevin Barry was an Irishman who was born in 1902 and was hanged in 1920 in Dublin Ireland by the British army. Kevin took part in an attack on the British Army which resulted in the death of three British soldiers. He was sentenced to death by hanging. I'd take a guess and say the reason why there were so many songs written about him is because of his age, he was only 18 years old when he was hanged in Mountjoy Prison in Dublin in 1920. Most of the songs that were written about Kevin were never recorded. The most famous song about Kevin Barry was recorded by The Wolfe Tones, the songwriter was anonymous. It's a kind of tradition in Ireland for rebels to have songs written about them when they die.
The next person to have many songs written about their life is another man who fought for Ireland during the same period as Kevin Barry is Michael Collins, who has 5 songs about him, on this site.
Irish folk song lyrics, chords and a whole lot more