Tutu met Archie Mountbatten-Windsor, the four-month-old son of the Duke and Duchess of Sussex, during their recent tour of Southern Africa and pictures of him planting a kiss on the baby's forehead were splashed in newspapers around the world.

Prince Harry and his wife later posted a picture of the encounter on their Instagram feed with the caption: "Archie loved meeting you."

On Monday, the Nelson Mandela Foundation was among those to pay tributes to the man affectionately known as "The Arch".  In a Twitter message, the foundation said: "The road has been long, but having you walk it with us has given us the strength to continue. Happy 88th birthday, Ukhule ungakhokhobi."

The FW de Klerk Foundation followed suit with a statement wishing Tutu, who tirelessly used his position as a cleric to contribute to the fight against the apartheid regime, good health.

"We join with our fellow South Africans in trusting for continued good health and much happiness for a giant among men, who has done much to contribute towards peace and reconciliation in our beautiful country. Happy Birthday, and may you have a blessed year, Arch!T," the foundation wrote.

An increasingly frail Tutu has received treatment for prostate cancer for years, and spent his birthday in hospital last year.

The Desmond and Leah Tutu Legacy Foundation collaborated with an exhibition titled The Forgotten Liberators in Cape Town, which opened on Sunday as part of celebrations to mark the archbishop's birthday.

Developed by Recherche International in Cologne, Germany it highlights the often forgotten role of Black and Coloured conscripts in World War II and details how Europe's colonies were exploited for food and war materials.

Tutu has continued to use his standing to criticise human rights violations in South Africa and the rest of the world, notably taking aim at Israel over the 

The ninth annual Desmond Tutu International Peace Lecture was taking place at the Cape Town City Hall on Monday evening. It would be delivered by Zimbabwean-born businessman and philanthropist Strive Masiyiwa. 

African News Agency (ANA)