George William was born in Ansbach in 1591 as the eldest son of Charles I, Count Palatine of Zweibrücken-Birkenfeld.

He was joint ruler in the Sponheimish condominium together with Margrave Wilhelm of Baden, whose counter-Reformationist movements he laboriously repelled.

George William married firstly on 30 November 1616 to Dorothea (1586–1625), daughter of Otto, Count of Solms-Sonnenwalde.

They divorced on 18 November 1642 because on 14 February of that year (and only four months after the wedding) Juliana gave birth a child, whose father was in fact Rheingraf Johann Ludwig of Salm-Dhaun.

George William married thirdly on 8 March 1649 to Anne Elizabeth (3 November 1603 – 3 June 1673), daughter of Louis Eberhard, Count of Öttingen-Öttingen.