Sir John Campbell Longstaff (10 March 1861 – 1 October 1941) was an Australian painter, war artist and a five-time winner of the Archibald Prize for portraiture.

[4] That month, French painter Jules Lefebvre's controversial 1875 nude Chloé was being shown in Victoria's National Gallery, and the Sunday Observance League objected to the trustees' decision to exhibit the painting on the Sabbath.

When it was covered with a black curtain, Longstaff, with eight other Gallery School students, three of whom were fellow Buonarotti Club members (Colquhoun, Frederick McCubbin and Louis Abrahams), wrote a letter to the press in protest.

[5] Longstaff occasionally joined other Buonarotti Club members on plein air excursions into the bush, and while his landscapes won admiration, he for the most part devoted himself to in-studio figure painting.

An early critical success of Longstaff's was the narrative painting Motherless, which won first prize in the National Gallery School's annual exhibition in 1886, and was purchased by Sir George Frederic Verdon.

Longstaff remained an active senior member of the Buonarotti Club until its demise in 1887 when he was given a well-attended farewell at the Melbourne Coffee Palace on 23 August, before sailing to London.

The occasion was his winning the National Gallery of Victoria's first travelling scholarship for his 1887 narrative painting Breaking the News, which sold for 100 guineas and became widely recognisable in Australia through reproductions,[7] even inspiring a 1912 film of the same name.

Also on Russell's advice, Longstaff attended the atelier of Fernand Cormon alongside the likes of Henri de Toulouse-Lautrec and Charles Conder, who had recently arrived from Australia and would go on to paint Topsy's portrait.