Fred Weatherly appears to have written Danyy Boy in TWO version.... Danny Boy, and Ellie Dear. According to his book about his years as a composer. It was written in 1910 , and set to a different tune. His sis sent Weatherly the music to Londonderry aire, and Fred immediatlty realized that it was a better tune than the one he had put to it. It's not about any particular event, but rather his attempt to write a somewhat maudlin parlor song about separation. It most certainly isn't about Da' sending his boyo to the conscription army to fight in WWI. The bomb that started it wasn't thrown in Seriabo for another 4 years.