 Macmillan attended Summer Fields School, Oxford (1903–06).He was Third Scholar at Eton College, but his time there (1906–10) was blighted by recurrent illness, starting with a near-fatal attack of pneumonia in his first half; he missed his final year after being invalided out, and was taught at home by private tutors (1910–11), notably Ronald Knox, who did much to instil his High Church Anglicanism.He won an exhibition to Balliol College, Oxford, but was less of a scholar than his elder brother Dan.