Cooke's documented life centred on Sydney, the capital of New South Wales. Founded as a British penal colony in 1788, the city grew into the largest urban centre in Australia and the principal city of its most populous state.
His formative path ran from university study in Sydney to his admission to the bar in New South Wales in 1954, before he became associated with Allen Allen & Hemsley, one of the city's established law practices.
Cooke studied at the University of Sydney, where he completed the degrees of Bachelor of Arts and Bachelor of Laws. Founded in 1850 by an act of the New South Wales Legislative Council, the university is Australia's oldest, and its law degree prepared graduates for entry into the colony's and later the state's legal profession.
He was admitted to the bar in New South Wales in 1954, after which he entered the city's commercial legal practice.
Cooke's professional career was centred on Allen Allen & Hemsley, a Sydney law practice whose origins reached back to 1822, when George Allen founded the firm that later became one of its predecessors. He served as a partner of the firm.
In the firm's earlier history, the Allen family dominated the partnership during the 1920s, while Alfred Hemsley, who joined the practice in 1894, and Norman Cowper, who worked there for more than fifty years and became senior partner, helped build it into one of Australia's leading law firms. Hemsley and Cowper both acted within the wider profession, and the Law Society of New South Wales counted several partners of the firm among its presidents.
In 1987 the firm joined the Australian Legal Group, an association of Australian firms that promoted cooperation without merging. A Sydney Morning Herald feature from the late 1980s identified Cooke among the firm's commercial lawyers, at a time when the Sydney office had more than 470 staff.
On 1 July 2001 Allen Allen & Hemsley merged with Arthur Robinson & Hedderwicks to form Allens Arthur Robinson, a combination that created one of the largest law firms in the Asia-Pacific region.
