 Eyles purchased the estate of Gidea Hall, in Havering, demolished the old mansion there in 1720, and built a new "elegant" house.In 1731, Eyles was the dedicatee of George Lillo's tragedy The London Merchant, a play later excerpted in French by Abbé Prévost who had served as Sir John's secretary and tutor to his son Francis.Eyles' wife died on 14 November 1735, and was buried at St Helen's Bishopsgate 9 days later.