The story goes that there was a high king of Ireland who had two sons. The older one went on to rule Ireland and the younger (my alleged ancestor) was jealous and staged a revolution. The revolution was unsuccessful and my ancestor had to flee to England. Was there ever a failed revolution like this that took place in Ireland or is this just family folklore?
Silken Thomas?
http://en.m.wikipedia.org/wiki/Thomas_FitzGerald,_10th_Earl_of_Kildare
That's the closest thing I can think of. Look, the Irish love a good tale and nobody more so than Irish emigrants. Nearly half of all Irish Americans I met told me that their great grandfather/uncle/whatever was in the GPO during 1916 or in the RA during the War of Independence. If all their claims were true, 100, 000 men would have been out during Easter week, not 1,800!
Your story is a nice tidbit, but probably not true.