Question: When did the King who the most valuable sovereign was struck for die?

Related documents: [0]  [DOC] Edward VIII (Edward Albert Christian George Andrew Patrick David; 23 June 1894 – 28 May 1972) was King of the United Kingdom and the Dominions of the British Empire, and Emperor of India, from 20 January 1936 until his abdication on 11 December the same year. [END] 
[1]  [DOC] The sovereign is a gold coin of the United Kingdom, with a nominal value of one pound sterling. Prior to 1932 it was a fully circulating coin within Britain's then Gold Standard currency. Today it is used as a bullion coin and is sometimes mounted in jewellery. The most valuable sovereign is the British Edward VIII 1937 struck for Edward VIII who abdicated, therefore these coins never entered circulation, and an example of one was purchased at auction in 2014 for £516,000. [END]  
Answer: 28 May 1972
28 May 1972