No, plunkett didn't write it, but he wrote a poem, Blood upon the Rose mentioned in the song. It was written by two very talented brothers, Sean & Fran O'Meara in 1985 and was a big it for Jim McCan of Dubliners Fame who sadly passed away in March this year. Grace was Plunkett's Fiance Grace Gifford who was brought to the jail to marry Oliver shortly before his execution, Already dying from TB Plunkett was allowed the service in his tiny cell surrounded by 8 armed soldiers such was the paranoia that an escape might be staged. Grace never remarried and served Sinn Fein with distinction until her death in the 1980's. PLunkett was perhaps destined for Martrydom, being a descendent of one of Eire's grat Martyrs Blessed Oliver Plunkett. Irish Tenor Anthony Kearns for me sings the best version of the son, available on You Tube