Prince William and Kate Middleton Under Pressure as They Face Backlash on Their First Caribbean Tour

Prince William and Kate Middleton are typically greeted with deference and excitement wherever they go — until now.

For the first time, the royal couple, who are in Jamaica for the fifth day of their eight-day tour of the Caribbean, are facing significant backlash on an official tour. Although they have received warm welcomes from many locals, they are also encountering mounting tensions in the Caribbean nations where William's grandmother, Queen Elizabeth, remains head of state.

This week's PEOPLE cover story takes a closer look at how the rising tide of social and economic justice movements — including calls for slavery reparations and indigenous rights expansion — are rapidly reshaping contemporary views of the monarchy at a time when it is in transition: As Elizabeth, 95, marks 70 years on the throne, William, 39, and Kate, 40, are increasingly the modern face of both the family and the institution.

Outside the U.K., the Queen remains head of state in 14 nations around the world (including Belize, Jamaica and the Bahamas) — an arrangement that critics say is excruciatingly outdated. "It is important as we turn 60 years old as an independent nation that we stand as 'adults' on solid ethical, moral and human justice grounds," Norah Blake, the co-organizer of a protest in Jamaica, told The Independent, "to say to Britain, who was once our 'parent,' that you have done wrong in enriching yourselves off of chattel slavery and colonialism."

The protests in Jamaica and earlier in Belize are only the latest evidence of the historic shift underway: Another Caribbean country, Barbados, broke ties with the Queen in November — voting in its first president — and a new report indicates that Jamaica may soon follow suit. In his speech at the ceremony that saw Barbados become a republic, Prince Charles recognized the "appalling atrocity of slavery, which forever stains our history," even as his presence there was criticized by some local leaders. Blake said both an apology for such atrocities and reparations are essential to moving forward: "Today we are setting the conversation of our future generations, for them to have something to build a brighter future."

It is Charles, 73, who will reign next alongside his wife, future Queen Consort Camilla, Duchess of Cornwall, 74, but "because of the ages of all the participants, there must be a feeling that long-term, the future of the British monarchy is more about William and Kate — spiritually, not in terms of actual succession," says historian Sarah Gristwood, author of Elizabeth: Queen and Crown.

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With the departure of Prince Harry and Meghan, Duchess of Sussex, from the working family, and the discrediting of Prince Andrew, "senior royals are a bit thin on the ground at the moment," says Gristwood. "Britain is never going to drop all its pomp and ceremony, and it was eventually going to be slimmer and economical. But it's doubtful even Prince Charles wanted it to lose weight so rapidly."

Royal historian Robert Lacey suggests that for the institution's long-term health, Charles should not reign as King outside of the U.K. "Why not jettison the hereditary foreign realm concept, securing Elizabeth II's place in history as the last 'Queen of the World'?" he asks.

For more on William and Kate's Caribbean tour and the surrounding controversies, pick up this week's issue of PEOPLE, on newsstands Friday

He points to the success of the Commonwealth realm, which comprises 54 countries that were once mostly part of the British Empire and today remain voluntarily linked to the U.K. The royals, Lacey offers, should "concentrate on developing the Commonwealth family as a more cohesive, diverse, international, open and forward-looking concept."