William was educated in Victoria, England, Canberra plus Perth and holds the degrees of Bachelor of Jurisprudence (1978) and Bachelor of Laws (1979) from the University of Western Australia.
In 1980 William was admitted as a Barrister, Solicitor and Proctor of the Supreme Court of Western Australia.
Between 1980 and 1985 Willian was employed by Messrs Stephen Chew & Company, Barristers & Solicitors of Perth, practicing in foreign investment, business migration, commercial & residential property plus business acquisitions, private and public company incorporations, trusts, mining law and succession law.
In 1980 William co-founded the practice of Jamieson Johnston of Perth, which continues to this day as Calverley Johnston. William then broadened his fields of practice to include property development plus sub divisions, commercial plus residential leasing, liquor licensing, motor vehicle plus personal injuries claims, franchising, association incorporations, debt recovery, arts law and further aspects of succession law.
In 2004 William retired from partnership to establish Jamiesons Lawyers of Nedlands and specialise in all aspects of succession law and property law.
William's pro bono contributions to the community have included Duty Counsellor undertaking criminal law assignments for the Legal Aid Commission of Western Australia for 5 years, succession lawyer rostered fortnightly providing advice at the Citizens Advice Bureau for 22 years and rostered general law adviser at the Subiaco Legal Service for 5 years and ongoing. In addition, William was honorary Legal Counsel for the Festival Fringe for 10 years, for the Armadale Noongar Corporation for 5 years and has provided free legal advice to members of the Thai community in Western Australia since 1983.
William was privileged to be appointed the Honorary Consul of the Royal Thai Consulate-General at Perth in 1983, having served as its visa officer since 1978 and represented the Kingdom of Thailand as Consul for almost 30 years. In recognition of service, His Majesty the King of Thailand decorated William with the Most Noble Order of the Crown of Thailand (1991) and the Most Exalted Order of the White Elephant (2006).
Representing Thailand was demanding plus varied and enhanced William's interpersonal skills as a diplomat, negotiator and mediator. Such experience conveyed an appreciation of the concerns of migrants, skills for assisting those from different cultures with communication difficulties and tools for dealing with bureaucracy.
William has in excess of 30 years experience as a Director of several companies variously trading as an exporter, importer, wholesaler and retailer in the wine, beer, tourism and music industries of both Australia and Thailand. Since 1996 William has been the Managing Director of an offshore company which holds a vineyard plus short stay accommodation facilities in the Margaret River wine region, which William manages.
William was the Treasurer of the Consular Corps of Western Australia for 10 years, a founder of the Festival Fringe of Western Australia of which he was a Board Member for 10 years and which has honoured him with life membership and is also a founder of Vershun Galore/Jamdown Vershun which for 38 years has presented a weekly programme of reggae music which William occasionally produces and presents.