"The Minstrel Boy" is an Irish patriotic song written by Thomas Moore (1779–1852) who set it to the melody of The Moreen, an old Irish air. It is widely believed that Moore composed the song in remembrance of a number of his friends, whom he met while studying at Trinity College, Dublin and who had participated in (and were killed during) the Irish Rebellion of 1798.
However, the song gained widespread popularity and became a favourite of many Irishmen who fought during the United States Civil War and gained even more popularity after World War I. The song is notably associated with organizations that historically had a heavy representation of Irish-Americans, in particular the police and fire departments of New York, Boston and Chicago and those of various other major US metropolitan areas, even after those organizations have ceased to have a substantial over-representation of personnel of Irish ancestry. The melody is frequently played at funerals of members and/or officers of such organizations who have died or been killed in service, typically on bagpipes. Unsurprisingly, given its lyrics, it is also associated with the Irish Army and with traditionally Irish regiments in the British, United States and other armies.