Theodore de Mayerne (1573–1655) was a successful and famous physician, serving in the royal courts of Europe. He is remembered most for advocating the use of chemical remedies in medical practice. He had a colourful personality and, despite living in England for 44 years, refused to own land and only spoke the language if necessary, staying true to his French-Swiss heritage. In his last years he became immobile through obesity, but was unconcerned, maintaining that ‘an evil soul never dwells in a fat body’. He was said to have died after drinking bad wine at a tavern in the Strand, London.

A skull is a common attribute in early portraits as a memento mori, a reminder of mortality, but in this case it could also be an allusion to Mayerne’s own developments in skull surgery.