Background: Laurence Kerr Olivier, Baron Olivier,  (; 22 May 1907 - 11 July 1989) was an English actor and director who, along with his contemporaries Ralph Richardson and John Gielgud, dominated the British stage of the mid-20th century. He also worked in films throughout his career, playing more than fifty cinema roles. Late in his career, he had considerable success in television roles.
Context: Olivier was born in Dorking, Surrey, the youngest of the three children of the Revd Gerard Kerr Olivier (1869-1939) and his wife Agnes Louise, nee Crookenden (1871-1920). Their elder children were Sybille (1901-1989) and Gerard Dacres "Dickie" (1904-1958). His great-great-grandfather was of French Huguenot descent, and Olivier came from a long line of Protestant clergymen. Gerard Olivier had begun a career as a schoolmaster, but in his thirties he discovered a strong religious vocation and was ordained as a priest of the Church of England. He practised extremely high church, ritualist Anglicanism and liked to be addressed as "Father Olivier". This made him unacceptable to most Anglican congregations, and the only church posts he was offered were temporary, usually deputising for regular incumbents in their absence. This meant a nomadic existence, and for Laurence's first few years, he never lived in one place long enough to make friends.  In 1912, when Olivier was five, his father secured a permanent appointment as assistant priest at St Saviour's, Pimlico. He held the post for six years, and a stable family life was at last possible. Olivier was devoted to his mother, but not to his father, whom he found a cold and remote parent. Nevertheless, he learned a great deal of the art of performing from him. As a young man Gerard Olivier had considered a stage career and was a dramatic and effective preacher. Olivier wrote that his father knew "when to drop the voice, when to bellow about the perils of hellfire, when to slip in a gag, when suddenly to wax sentimental ... The quick changes of mood and manner absorbed me, and I have never forgotten them."  In 1916, after attending a series of preparatory schools, Olivier passed the singing examination for admission to the choir school of All Saints, Margaret Street, in central London. His elder brother was already a pupil, and Olivier gradually settled in, though he felt himself to be something of an outsider. The church's style of worship was (and remains) Anglo-Catholic, with emphasis on ritual, vestments and incense. The theatricality of the services appealed to Olivier, and the vicar encouraged the students to develop a taste for secular as well as religious drama. In a school production of Julius Caesar in 1917, the ten-year-old Olivier's performance as Brutus impressed an audience that included Lady Tree, the young Sybil Thorndike, and Ellen Terry, who wrote in her diary, "The small boy who played Brutus is already a great actor." He later won praise in other schoolboy productions, as Maria in Twelfth Night (1918) and Katherine in The Taming of the Shrew (1922).  From All Saints, Olivier went on to St Edward's School, Oxford, from 1920 to 1924. He made little mark until his final year, when he played Puck in the school's production of A Midsummer Night's Dream; his performance was a tour de force that won him popularity among his fellow pupils. In January 1924, his brother left England to work in India as a rubber planter. Olivier missed him greatly and asked his father how soon he could follow. He recalled in his memoirs that his father replied, "Don't be such a fool, you're not going to India, you're going on the stage."
Question: Who were Olivier's parents?

Answer:
Revd Gerard Kerr Olivier