A Francis Bacon triptych that depicts the aftermath of Russian revolutionary Leon Trotsky’s 1940 assassination in Mexico City is expected to fetch up to $75m (about R1.1bn) when it goes under the hammer next week.

Described by Christie’s as among the iconoclastic Irish-born painter’s last great works, Triptych 1986-7 features then US president Woodrow Wilson leaving the post-World War 1 Treaty of Versailles meeting in 1919 and Bacon’s friend, John Edwards, on its other two canvases.

The British auction house’s price estimate for the work, part of a March 1 sale in London of 20th- and 21st-century masterworks, is $48m (about R732m) to $75m...