He specialised in depictions of animals and exotic, "primitive" subjects as seen in the first sculpture he ever exhibited, A Victorious Group of Huns from 1889.

[2] His most important patron was Carl Jacobsen, founder of Carlsberg Brewery, who among other pieces, ordered Thor Driving Across the Arch of the Sky (1897).

Bonnesen's last great patron was jurist Harald Plum, who had the huge sculpture group Thor at War with the Jötunns (1891) placed on his private island, Thorø.

These include an equestrian statue of King Christian IX which stands on the market place in the centre of Esbjerg, Denmark.

Other notable works include Adam and Eve at the body of Abel (1900) and Two Lions in the Danish National Gallery as well as several statuettes in The Hirschsprung Collection.