The Murder of Sir Edmund Godfrey (1936)
My review:
Although renowned for his superb detective fantasies, Carr's masterpiece of history and detection (arguably the same philosophy, as this, the works of Lillian de la Torre and Josephine Tey's Daughter of Time all testify) is his reconstruction of The Murder of Sir Edmund Godfrey. Despite an obvious anti-Whig bias and his adoration of Charles II (the only great monarch between Elizabeth and George III), his historical method is excellent, weighing up the odds impartially while drawing a most dramatically colourful picture of Restoration London. The theories are brilliantly argued, and equally brilliantly demolished, and the final solution is quite convincing. Superb.