Amid the outbreak of the Second World War, he enlisted into the XII Brigade, Royal Horse Artillery (RHA) on 20 October 1939.

[3] That same year, he began work in the West Africa Department of the Commonwealth Office, and as the Counsellor within the British High Commission in India until March 1963.

[5][4] Gautrey's diplomatic career began after being appointed as the High Commissioner to Swaziland from 2 September 1968 to 1971.

[11] On 16 January 1975, a celebration was held at Istana Darul Hana in conjunction to the completion of his three years service to Brunei.

[7] Peter Gauntrey was given the title of Yang Terutama (His Excellency) Dato Laila Utama by Sultan Hassanal Bolkiah.