The long, happy and unlikely marriage of the great Conservative leader Disraeli and his wife Mary Anne, 12 years his senior, is analysed thoughtfully in Daisy Hay’s new book. Reading between the lines, it is possible to see the Disraelis as a Victorian power couple not unlike the Underwoods in Netflix’s remade House of Cards — he, high on his own oratory; she, a valuable campaign asset; together, a marriage that is child-free and (with his sexuality in question) built on blackberries at bedtime.