William Maurice II of Isenburg-Philippseich was the son of William Maurice I, Count of Isenburg-Büdingen-Birstein (1657–1711) and his wife, Countess Anna Amalie of Isenburg and Büdingen (1653-1700), the eldest daughter of Count Johann Ernst I of Isenburg-Büdingen (1625-1673).
[2][3] On his first marriage on 9 January 1712, William Maurice II married in Birstein to Burgravine Amalie Luise of Dohna-Lauck (1680–1723), daughter of Count Christoph Friedrich of Dohna-Lauck (1652-1734) and his wife, Countess Johanna Elisabeth of Lippe-Detmold (1653-1690).
From their marriage came the following issue: After Amalie's death, William Maurice married on 2 April 1725 in Gedern to Countess Philippa Luise of Stolberg-Gedern (1705–1744), daughter of Count Louis Christian of Stolberg-Gedern (1652-1710) and his wife, Duchess Christine von Mecklenburg-Güstrow (1663-1749).
From this marriage they had the following issue:[4] William Maurice embarked on a military career and became a major general in the Upper Rhenish Circle.
As an inheritance of the Offenbach line, he received the villages of Götzenhain, Offenthal,Sprendlingen,Urberach and Münster in the Dreieich.