At his death in Paris in 1829, Bridgewater's titles became extinct. He left the majority of his estates, including Ashridge, to
John Hume Cust, Viscount Alford, heir to
Earl Brownlow. Alford's grandmother was Lady Amelia Egerton, great-granddaughter of
John Egerton, 3rd Earl of Bridgewater. The estates drew income of £70,000 annually (). However, Bridgewater left the estates with a peculiar stipulation: Alford could only keep them provided he be raised to the peerage as Duke or Marquess of Bridgewater, and that if he failed to do so, the estates would go to his younger brother the Hon.
Charles Henry Cust, with the same requirement. "Provided also, and I declare my will to be, that it shall happen that the said John Hume, Lord Viscount Alford shall not acquire the title and dignity of the Duke Marquis Bridgewater, to him or the heirs male of his body, with the immediate limitation over of such title and dignity to the said Charles Henry Cust and the heirs male of his body, or to the heirs male of his body if he shall be dead leaving issue male, and also, that the said Charles Henry Cust shall not acquire the title and dignity of Duke or of Bridgewater, to him and the heirs male of his body, then such case the use and estate hereinbefore directed be limited to the heirs male of the body of the said Charles Henry Cust shall cease and be absolutely void." Alford assumed the name and arms of Egerton, but died in January 1851, aged only 38. His eldest son,
John Brownlow Cust, just shy of 9 years old, adopted the Egerton surname as his father's heir. Charles Cust then adopted the surname Egerton and in February 1851 sued his nephew for the Bridgewater estates, as his brother had failed to meet the conditions of Bridgewater's will. More than 3,800 manuscripts have been purchased using the Egerton fund. He also left £8,000 () at the disposal of the president of the
Royal Society, to be paid to the author or authors who might be selected to write and publish 1,000 copies of a treatise
On the Power, Wisdom and Goodness of God, as manifested in the Creation. The resulting eight
Bridgewater Treatises first appeared between 1833 and 1836, and afterwards in
Bohn's Scientific Library. ==See also==