Her mother was a daughter of Donough MacCarty, 1st Earl of Clancarty and thus belonged to the MacCarthy of Muskerry dynasty, a Gaelic Irish family that descended from the kings of Desmond.

[17] Sarsfield was at that time the eldest living son of a landowner from County Kildare and an experienced soldier, serving in the Irish Army of James II during the Williamite War in Ireland.

[19] Sarsfield rose rapidly to become one of the leaders of the Jacobite movement in Ireland, noted in particular for the Ballyneety Raid on King William's artillery train shortly before the Siege of Limerick (1690).

After the surrender of Limerick following a second siege in 1691, Lucan led the defeated Irish Army to France to continue serving the exiled James II, an event known as the Flight of the Wild Geese.

[23] In France she was admired for her beauty and is said to have introduced "les contredanses anglaises" (English country dance) to the French Court.

In April 1693 Honora and Patrick had one son:[27] He was named after James Francis Edward Stuart, the Jacobite Prince of Wales, later known as the Old Pretender.

[30] It has been said that Catalina Sarsfield, who married a German adventurer, known for having briefly established himself as King Theodore of Corsica, was a daughter of Honora and her first husband.

[33][citation needed] After Lucan's death the dowager countess joined the Jacobite court-in-exile at Saint-Germain-en-Laye near Paris.

Berwick was an illegitimate son of James II and Arabella Churchill, and pursued a brilliant military career since an early age.