For William, who celebrates his 28th birthday on Monday, reports of an impending engagement will be further fuelled by the news his girlfriend Kate Middleton has moved in with him.
Taking their romance to the next level, the couple are said to be living together at the prince's home in North Wales while he trains to become an RAF search and rescue pilot in Anglesey.
Sources close to them say that Kate, also 28, has given up her full-time job at Party Pieces – the internet party planning company owned by her parents.
"Kate no longer works on a full-time basis at the offices of Party Pieces as those closest to her feel it wouldn’t be a good fit for a future queen to be working on a family-run website," one friend told the Daily Mail.
"William will be training for three years and they agreed that Kate should be closer to home. They go out to the shops in Blaenau Ffestiniog for groceries and she's settling in well."
Meanwhile, William's brother Harry is facing a less certain future with his love, Chelsy Davy.
This week, it was reported that the Zimbabwe-born blonde, who moved to England two years ago, has decided she wants to return to Africa and her family.
While senior royals have apparently said that the couple are still "very much an item", Chelsy, 24, is believed to have told the prince that she misses home.
She is said to want to be closer to her parents, Charles and Beverly, and brother Shaun in Zambia - the family moved there from Zimbabwe last year. She also hopes to further pursue her legal career in South Africa.
Harry, who is holidaying in Africa for a few days following the tour with William, is about to begin training to become an Apache pilot, and is therefore unlikely to be able to jet to Zambia on a regular basis.
"Truthfully, the only way I can see this relationship working in the long term is for Harry to give up his royal life in England and move to Africa permanently," a friend of Chelsy said. "But it is unlikely he will ever be allowed."
That solution, it seems, would be ideal for Harry. While in Lesotho visiting his charity last week, the 25-year-old prince was asked to jot down what his future ambitions were. "Professional surfer, wildlife photographer, helicopter pilot and live in Afrcia," he wrote.
But with his commitments to the Army – he may return to Afghanistan in the next 18 months – it seems Harry, for the time being, will be staying put.