The following year, however, he suffered a severe depression accentuated by the sudden death of a close friend at Oxford.

He visited the Americas, including Salt Lake City and the Rocky Mountains, and travelled south from there into Mexico.

He undertook a special journey to Fez in Morocco to study the philosophy of Plato as taught there, while there he secured entrance to the Great Mosque by posing as an Islamic pilgrim.

[2] When he returned to Britain he adopted the profession of an architect and apprenticed in the office of Sir George Gilbert Scott, and then as a partner in his father's business at Storey's Gate, Westminster.

[2] Middleton never ceased to pursue his favourite studies of art and archaeology, and even went through a course in the schools of the Royal Academy.

His vast knowledge became well known and brought him many friends including William Morris, with whom Middleton travelled in Iceland.

He was also honoured with a doctor's degree at the University of Bologna and in 1888 elected a fellow of King's College, Cambridge.