Alphaeus Hamilton Zulu was the only son of Johannes and Miriam Kolo Zulu (nee Hlabisa). His father was a policeman and a farmer. His father died when he was a young boy and his mother died in the early 1940s.
Zulu started his primary schooling at Hlazakazi Magogo at Nguthu and completed his secondary schooling at New castle Intermediary. In 1920 he started to train as a teacher at Milton school in Alcockspruit, going on to qualify as a teacher at St Chad's College in Ladysmith in 1925. In 1926 he was appointed principal of the intermediate school in Umlazi. He held that post for five years. He studied privately and passed his junior certificate. In 1931 he became head teacher of Umlazi Combine School.In 1935 his private studies paid off and he obtained his matriculation certificate. He was enrolled at the University of Fort Hare in the Eastern Cape. He completed a BA degree with a distinction in Social Anthropology. Three years later he experienced a turning point in his life, which afterwards he identified as his 'calling' from God, and in 1939 he entered St Peter's Anglican Theological College in Johannesburg. He studied there for two years and earned himself a Licentiate in Theology. Later on Zulu joined the interdenominational African Ministers' Association of South Africa (IDMASA), although he had been influence mainly by the teachings of the Anglican Church.
In December 1940 he was ordained to the ministry as deacon. Later he was appointed assistant curate at St Faith's Mission in central Durban. In 1942 he was ordained priest-in-charge at St Faith's and remained there for 20 years. His sterling services were recognize by the Diocese of Natal in 1957 when he was made honorary canon of St Saviours Cathedral in that Diocese. In 1960 he was appointed Bishop suffragan of the Diocese of the St Johns in the Transkei, where he stayed for six years and founded the Transkei council of Churches. While a priest at St Faith's mission in the 1950s, he founded a religious group called Iviyo Lofakasi (meaning 'witnesses to God's wonders') with a friend, Canon Mbata. In 1960s, as a bishop in Zululand, he saw a need for a religious order for Anglican nuns and established a convent in Melmoth. At the same time (early 1960s), he was elected president of the World Council of Churches (WCC) and was one of the leading figures in the organization for seven years. In 1968 he was elected Bishop of Zululand and Swaziland. A political controversy ensued as his predecessors were white and he was black. Some white families refused to let him lay hands on their daughters' heads (as is the custom during confirmation). Some had such a strong conviction about this that they left the church and joined other church affiliations. The government refused him permission to occupy his official bishop's residence at Bishop's Court in the town of Eshowe.
The church thus had to build him a house near Gezinsila Location. His episcopate was never easy. During his overseas visits he, for example, had to wait for long periods for his passport and travel documents because they were confiscated by government officials. This means that he could not attend important conferences overseas, making it difficulty for him to fulfil his role asPresident of the (WCC). He was Bishop of Zululand for nine years until his retirement at the age of 70 in 1975. He was a humble, humorous, dedicated, intelligent and spiritual being. He tried to live his entire life as the Christ he loved, followed and tried to emulate. He made a point of helping disadvantaged students by arranging for financial aid from his overseas contacts and South African associates. He believed in passive resistance and he refused to condone violence. Hence his experience of rejection later as a president of the WCC when he refused to support proposals for violent solutions to South Africa's problems.
Between 1958 and 1984 he travelled extensively, visiting the UK, America, and other parts of Africa. He also attended the Lambeth Conference in London and an Episcol Church Convention in Detroit in the company of Joost de Blank*, who was the Archbishopof Cape Town at the time. In 1942 he and Chief Albert Luthuli co-founded the Natal Bantu Cane Growers' Association. By so doing families could start their own small gardens and thus become self-sufficient. Zulu and Luthuli both joined the African National Congress in the same year and both believed that South Africa's political problem could be resolved peacefully. After 1975, having retired as Bishop of Zululand, he broke with the ANC and accepted office as National Chairperson of the Inkatha Freedom Party. He did this because earnestly believed the party's mission statement of non-violence. After he was appointed speaker of the KwaZulu Legislative Assembly, he was rejected by some of his friends and many Zulus were hostile towards him.
Zulu was also a member of the Zulu Royal Dynasty. Zulu was passionate about music. At St Faith's, where he was priest, he would stop the choir immediately if the members went off-key to give them the correct note. Zulu devoted his energies and talents to promoting a spirit of self-help and self-reliance, teaching people to take responsibility for their needs.
Zulu married Adelaide Magwaza on 3 January 1929. They had six daughters and one son. After the death of his first wife, he married Lillian Mkhize on 23 February 1985.