[1]: 8 [5] The attack at Pinjarra was in response to sustained aggression by the Binjarebs, including robberies and murder of settlers and members of other Nyungar tribes.

The Pinjarra Massacre was the culmination of increasing tension and violence between newly arrived settlers, who were appropriating the land for farming, and the Noongar peoples, who lived on it as hunter-gatherers.

[6]: 13 [7] Despite this, some of the younger generation of Binjareb (notably Calyute's son Monang and another individual called Denmar) later became involved with the newcomers.

Monang and Denmar, both involved in the murder of Nesbit, and originally on the list of "wanted" Nyungar men, in fact became the first "native" policemen at Pinjarra in 1838.

[5] Following the Binjareb looting, by means of armed robbery, of the flour mill that provided rations to settlers and Noongars in the district, as well as the murder and mutilation of Nesbitt,[5] Captain Frederick Irwin, the lieutenant governor in Stirling's absence, is said to have inflamed the situation by adopting a soldier's attitude to crush a warlike group of Aboriginals and reduce them to a state of subjection.

[citation needed] It was this unyielding, overbearing attitude that had alienated [Irwin] from the body of Swan River settlers and caused them to burn him in effigy on the eve of his departure.

It was a narrow, regimented view of frontier problems and, perhaps, part of the blame for the Pinjarra massacre can be attributed to Irwin and his unsympathetic administration of Aboriginal affairs during James Stirling's absence.

[citation needed] In response to calls from Pinjarra settlers for protection against the increased hostility of local Binjareb Noongars led by Calyute, Stirling organised a mounted force of police, bushmen and ex-soldiers.

[9] This followed an earlier failure by Surveyor General Septimus Roe and pastoralist Thomas Peel, who had led an expedition to the area with the goal of improving security and negotiating peaceful co-existence.

[citation needed] Stirling had wanted to begin on 17 October, but a Murray man seen in Perth was suspected of being a spy for Calyute and so the expedition was delayed one week.

Leaving Peel's farm they crossed the Serpentine River and went forward to the Murray delta where tracks of a sizeable group of Aboriginal men women and children were discovered heading towards Pinjarra.

[citation needed] In the late afternoon, they camped at Jinjanuk, 16 kilometres (10 mi) from the mouth of the Murray River, so that they could begin the attack early next morning when they judged the Aboriginal group would be least prepared.

By 8:00 am, the party had rejoined the Murray where the river was 30 metres (98 ft) wide, between steep red loam banks, continuing northwards to cross the Oakley brook at about 8:35 am.

[citation needed] The Aboriginal men gathered up their spears and woomeras, as the women and children fled towards the river, where Stirling, Meares, Peel and 12 others were waiting in hiding.

[citation needed] Ellis was soon in a melee with the Noongars, and Norcott, recognising a troublemaker called Noonaar, shot him with his double-barrelled shotgun, causing the first casualty.

[citation needed] Ellis had been dislodged from his horse but Norcott continued pushing the group into the river where they were caught in a withering crossfire.

60–70 Aboriginal men, women and children in the camp had been subjected to intensive fire of 24 guns for an hour, and for another half-hour the survivors were hunted through the bush.

[14][15] Later that week The Jackets of Green, a folk ballad honouring Ellis, was published and sheet music sold at hotels in Guildford and Perth.

[16] The colony's native interpreter, Francis Armstrong, was given a woomera by a survivor shortly after the ambush, a description of which was printed in the Perth Gazette; an image drawn on the object depicted a river, horses, humans and the graves of the slain.