Britain's Prince William and his wife Catherine celebrate their first wedding anniversary Sunday, marking the milestone in private after two billion TV viewers watched them wed in 2011.

A spokesman for St James's Palace said they would enjoy the day "privately", having spent the weekend "with friends who have a celebration".

British newspapers lined up to praise the pair who have been credited with reviving public interest in the monarchy.

"Kate the Great wins us over," the Sunday Times said, while the Sunday Telegraph said of the royal family: "It's only been 12 months and already we wonder: how did they ever manage without her?"

Even the traditionally anti-monarchist Independent produced a "cut-out-and-weep guide" on Saturday to the couple's first 12 months.

After honeymooning in the Seychelles, William and Catherine toured Canada and California and made polished public appearances in Britain, with more ahead for Queen Elizabeth's diamond jubilee in June and the London Olympics.

Catherine, known to many as Kate, appears to have taken to the royal life with ease and has become a fashion trendsetter, even appearing on Time magazine's list of the world's 100 most influential people.

William, the second in line to the throne, earlier this year spent six weeks as a search and rescue pilot in the Falkland Islands, infuriating Argentina, which claims the islands as its own.

The pair are set to tour Singapore, Malaysia, Tuvalu and the Solomon Islands in September.

Speculation has been rife as to when the two will produce a royal heir, but they have made it clear they will not be bound by any timetable, and fans have so far had to make do with news of the couple's cocker spaniel puppy, Lupo. (AFP)