[6] Rhodesian intelligence, which had been monitoring ZANLA's activity and preparations, grew curious when over a four-week period in November 1972 sources of information suddenly began to "dry up", in the words of historian Alexandre Binda.

This false veneer of security was smashed on 21 December 1972 when a group of ten ZANLA cadres led by Rex Nhongo[8] attacked the white-owned Altena Farm near the north-eastern village of Centenary, about 30 kilometres (19 mi) west of Mount Darwin.

Having established a presence in the nearby Chiweshe Tribal Trust Territory, a cadre of Zimbabwe African National Liberation Army (ZANLA) insurgents armed with AK-47s, hand grenades, and at least one light machine gun (most likely an RPD) trekked about six miles to reach Altena.

[3] A list of white farmers in the Centenary district was drawn up and de Borchgrave was marked for elimination due to his poor reputation among black farmworkers.

[6] Rex Nhongo was later stopped and questioned by some members of the British South Africa Police, but as his identity documents were in order and he had concealed his weapons, he was not detained.

[4] ZANLA claimed that Rhodesian troops posted within shouting distance of the home responded to the scene and saved the lives of Dalgleish and his guests by engaging the assailants.