"Ag Críost an Síol" (Irish: [ə ˈcɾʲiːsˠt̪ˠ ə ˈʃiːlˠ]; meaning "Christ's is the seed") is an Irish poem, later set to music by Seán Ó Riada and subsequently widely used as a hymn.
There are conflicting accounts of the origins of Ag Críost an Síol.
[1][2] Another source[3] says that it was in fact written in 1916 by Father Michael Sheehan (Micheál Ó Síocháin) of Waterford, a co-founder of Coláiste na Rinne, the Irish College in An Rinn, County Waterford, who later became assistant Archbishop of Sydney, Australia.
Sheehan, credits the words to the similarly named Fr.
[6] The words were set to music by Seán Ó Riada as the offertory hymn in his 1968 setting of the mass, Ceol an Aifrinn (literally, "Music of the Mass"; known in English as the "Ó Riada Mass"),[7][8] which is used to close a number of Irish traditional music gatherings, such as summer schools.