He retired from royal public duties back in 2017 and has only stepped out for rare engagements ever since, usually alongside the Queen.
However, Prince Philip will now be seen even less as he officially hands over the Patronage of The Chartered Management Institute to Sophie, the Countess of Wessex.
"The Duke of Edinburgh has officially handed over the Patronage of The Chartered Management Institute to The Countess of Wessex," the Royal family tweeted on Wednesday.
"This evening The Countess will attend an event to celebrate the outstanding achievements of UK managers from across industry.
"The Duke of Edinburgh was Patron of CMI Managers - the professional body for management and leadership - from 1992. During that time the Institute led the debate on the future o management and leadership, the gender pay gap, and employee wellbeing and engagement.
"The Countess is an active supporter of UK industry, and Founder and Chair of the Women's Network Forum, an organisation which works to promote women's success in the workplace through best practice sharing and supporting those making gender equality a reality."
The announcement comes just weeks after Prince Philip joined the Queen, 93, at a lunch for members of the Order of Merit at Windsor Castle on May 7 where they posed for a group photo.