Knowles was born in England in 1810. His father John Knowles, a Wesleyan minister, "was induced to let his son indulge his natural disposition for travel and adventure"; Knowles was an early emigrant to the
Swan River Colony (later Perth). The colony experienced difficulties and in April 1830 he arrived in
Hobart Town, where he was a tutor of drawing and languages. He later moved to
Sydney, where distant relatives lived. The
Theatre Royal opened in 1832 and, although he had no theatrical experience, he became an actor at the theatre. He was unwilling to lose the friendship of his Wesleyan relatives, and at first appeared as Mr Cooper, but eventually he left the Methodist church. From the second season he used his own name; he was acting manager, and played melodramatic, tragic and comic roles. He played major Shakespearian roles; he was Australia's first Hamlet and King Lear. He was a favourite with Sydney audiences. Although he was criticized for not closely studying his parts, it was acknowledged that he played many roles and had managerial duties. He had a relationship with
Harriet Jones, an actress who had appeared in Sydney since 1826; from 1839 she was usually known as Mrs Knowles. In May 1837 he sailed for England to join his brother's legal firm; he returned, for his health, in October 1838. Having seen
William Macready and other notable actors in London, his subsequent acting was more refined. ==Rival theatres in Sydney==