The most impressive testimony to Buchan’s classical scholarship remains the biography of Julius Caesar (1932) and that of Augustus (1937). Augustus covers an enormous subject at a gallop and its style is a delight. As a politician and administrator (he was Governor-General of Canada at the time) Buchan showed real insight into Augustus’s achievement in establishing an empire that lasted one thousand five hundred years (if the Byzantine empire is included).
_{Michael & Isobel Haslett, 2001}

Available to read at https://penelope.uchicago.edu/Thayer/E/Gazetteer/People/Augustus/BUCAUG/home.html