Today, 17 June, is the official birthday of King Charles III. This celebration of the British Sovereign is always held on the second Saturday of June.So what do you need to know about our king – and the work he’s done for charities?For over 40 years, King Charles III – formerly known as The Prince of Wales – has been a leader in identifying charitable need, then driving forward charities to meet it. Together with the Queen Consort, formerly The Duchess of Cornwall, they are president or patron of more than 500 organisations.Charles is the president of 19 charitable trusts, all of which are gathered together under the umbrella of the Prince’s Charities. These charitable trusts raise over £100 million annually for their chosen causes, all of which are overseen by Charles himself.The Prince’s Charities also has branches in Canada and Australia, to help Charles further his charitable endeavours around the globe. Charles has frequently toured both of these countries attending charitable events in an effort to bring aid to youth, the disabled, the disadvantaged, the arts, the environment and so many more causes.Charles is a patron of over 420 charities and started his charity The Prince's Trust with his Navy severance pay of just over £7,000 back in 1976. To date, The Prince's Trust has helped over 875,000 disadvantaged young people into employment or business.Charles has also founded a number of initiatives to try and help communities locally and globally, across the world. Many of these focus on his passion for sustainability.One of these is The Prince’s Accounting for Sustainability Project (A4S), founded in 2004, which aims to inspire action by finance leaders to drive a fundamental shift toward resilient business models and a sustainable economy.Another is the campaign for wool, where Charles sought to repopularise wool as a natural fire-retardant and sustainable fabric, expanding the market for both British and Commonwealth wool as well as promoting the awareness of its environmental benefits.Charles also set up the Prince’s Countryside Fund (PCF), helping to improve the quality of life for those living and working in rural areas. The Prince’s Countryside Fund has a vision of a confident, robust and sustainable agricultural and rural community which is universally appreciated for its vital contribution to the British way of life and fits to support future generations.You can find out more about the King's charity work on the Royal Family website.