, . On 18 January 1883, Horner was married to
Frances Graham, daughter of
William Graham. Through her, he became associated with the social group known as
The Souls, several of whom were frequent visitors to Mells, including the Liberal MP
H. H. Asquith, who later became prime minister. Together, Frances and John were the parents of four children: Through his second daughter Katharine, he was a grandfather of Lady Helen Asquith
OBE, who did not marry but was a teacher and school inspector, Lady Perdita Asquith, who married
William Jolliffe, 4th Baron Hylton and had three children (including the actress
Anna Chancellor), and
Julian Asquith, 2nd Earl of Oxford and Asquith, who married Anne Palairet and had five children (including
Raymond Asquith, 3rd Earl of Oxford and Asquith). ==References==