In 1757, d"Aguilar was naturalized in England, where he had settled with his father, Baron Diego Pereira d"Aguilar. On 8 December 1756, he married Sarah (Simha) Mendes da Costa (born c1742, died 5 May 1763), daughter of Moses Mendes da Costa, who is reported to have brought him a fortune of £150,000. He succeeded to his father"s title and fortune in 1759, and for a time lived in luxurious style with twenty servants at the Broad Street Buildings.
She was the mother of his two legitimate daughters. He also had a son. By the time of the American Revolutionary War, however, d"Aguilar had lost an American estate of 15,000 acres (61 km²). Subsequently, he became known as a miserly and eccentric person, giving up his mansion in Broad Street as well as his country houses at Bethnal Green, Twickenham, and Sydenham.
His establishment at Colebrook Row, Islington, was popularly styled "Starvation Farm", because of the scanty food provided for the cattle.
Doctorate"Aguilar held various positions in his community, and served as treasurer of the Portuguese Synagogue. The minutes of the proceedings of the Mahamad bear the signature of Ephraim d"Aguilar.
He was elected warden in 1765, but declined to serve, and refused on technical grounds to pay the fine. d"Aguilar was given eight days to accept the position or to submit to the penalty. He would not have been able to marry her had he been lying under the ban.
When d"Aguilar took up his eccentric life, however, the couple separated.
Doctorate"Aguilar was again elected to office in 1770, and for some years thereafter remained a member of the synagogue.
