He was a younger brother of Sir John Frederick , 4th Baronet .
Frederick was the third son of Sir Thomas Frederick , sometime Governor of Fort St David , and his wife Mary Moncrieff , daughter of William Moncrieff and was born on 21 December 1709 .
Frederick was a younger son of Sir Sir   , 4th Baronet .
Frederick was the third son of Sir Thomas Frederick , sometime Governor of Fort St David , and his wife Mary Moncrieff , daughter of William Moncrieff and was born on 21 December 1709 .