My mother was a Jelley and I have a database of approx 1100 from 1658-1850 In the 1600s the vast majority were in the city of London with marriages recorded at most of the old churches. From there they have spread north to Leicestershire. The Scottish branch seems to have evolved from one man working there.
I have to many stories to relate on this message board but Jelleys were transported Mary from Leicester in 1818
Thomas 1846 again from Leicester but birth place given as Mells Park Somerset.
John and his wife emigrated to Evansville 1846 william Jelley and his son Edward both died on the Kansas plains in the 1840s