Battle of Landen
Berwick fell in love with General Patrick Sarsfield's 19-year-old pregnant widow. They married in Saint-Germain-en-Laye (Yvelines) on 26 March 1695, two years after Sarsfield's death in the Battle of Landen on 29 July 1693. This was Honora, Countess of Lucan (formerly known as Lady Honora Burke or Lady Honora de Burgh; b. Portumna Castle, Co. Galway, 1674 – d. Pézenas, 16 January 1698), the daughter of John Burke, 9th Earl of Clanricarde, an Anglo-Irish peer. Berwick raised Sarsfield's son, James Sarsfield, 2nd Earl of Lucan, who died childless in 1718, as his own. Berwick and the Countess had a son: