Hi there, whilst I know there's likely to have been many Byrne's in Dublin, my Grandfather (Edmund Leo Byrne - known principally as Ned Byrne but also it would seem referred to as Eddie Byrne (i've got a couple of letters where he's called that but it's mainly 'Ned')) was involved in IRA activity during this period (ostensibly, it would seem, as dispatch carrier for Michael Collins between Liverpool and Dublin (my grandfather was in the Merchant Navy aboard the SS Blackrock and carried dispatches, and aided in the transit of arms and wanted men between Liverpool and Bristol to Dublin - i have some testimonals dating from the 1920's from former IRA/IRB members to this effect - including Neill Kerr and, also, one or two others he aided following their escape from Usk prison in 1919). Anyway, he had, i believe, 6 or 7 brothers who were also involved in 'the movement' including a Willy Byrne, a Vincent Byrne and a Gus Byrne (i don't know the names of the others alas) and I don't know if it's possible that he/they were your Grandfather's brother(s)? I believe the family home during the 1916-21 period was 7 St James' Street, Dublin (don't know if all the brothers were living there at this time or whether some had moved/married/were in safe houses). Anyway, if any of this is familiar I'll be happy to share my information with you and be very glad of anything you can help me fill-in my gaps with.