Errol Shanley was born in Durban in April 1911, the son of Arthur Stanley, who was born in London of Irish parents and Anna Else Bernhardt born in Hamburg Germany. He attended Epson Road Boys School in Greyville and after completing his primary school, aged age 17, he went to work for a firm of building suppliers and joined the Shop Workers Union.
In 1933 he joined the Communist Party of South Africa (CPSA) and became active in the party-inspired Anti–Fascist League, serving as its Natal secretary. During the Second World War, Errol was the secretary of the Natal section of Trades and Labour Council. In the 1940's Arthur joined the Distributive Workers Union. When HA Naidoo and his wife Pauline Podbrey left Durban to settle in Cape Town, Errol took over the secretary ship of the Sugar Workers Union.
Errol married Dorothy on 6 December 1941. In 1943 Errol failed in his bid to enter Parliament as the CPSA candidate for the Umbilo constituency. After the German invasion of the Soviet Union, Errol, like most CPSA members, joined the army and was member of the 2nd Field Army Ambulance Corp. After the banning of the CPSA in 1950, Errol played a leading role in the formation of the Congress of Democrats (COD), the 1952 Defiance Campaign, the Freedom Charter Campaign, and the convening of Congress of the People.
On 5 December 1955 Errol and Dorothy were arrested with 154 others and charged with high treason following the events at the Congress of the People and the adoption of the Freedom Charter. The charges against them, however, were withdrawn in December 1957. Between 1957 and 1960, Errol was a member of the underground Communist Party. He was arrested in March 1960 during the State of Emergency. After his banning, he was employed as an insurance agent.
Errol and his wife left for Britain at the end of 1972. There he found work in the British labour movement and also worked as a volunteer in the African National Congress's London office.
Dorothy died on 4 April 2001 and Errol one year later on 23 March 2002.