MOMENT IN WORLD HISTORY

Whether a boy or girl, the baby will be third in line to the throne, pushing Prince Harry into the fourth place in the royal list, as the government has changed the rules of succession. Previously male heirs took precedence over females.

The baby is due to be delivered by Marcus Setchell, the Queen's former gynecologist, in the private wing where a normal delivery costs 4,965 pounds ($7,400) and each extra night around 1,000 pounds.

Mark Stewart, a photographer specializing in royals, was one of the first to set up in the press pen to get a front row spot for when the royal couple and baby emerge from the hospital.

"Globally there is huge interest in the royal baby, particularly in America, and I wanted to get a front row seat to world history," said Stewart whose ladder is chained in place.

The gender of the baby remains unknown with the couple saying they do not know who is coming despite wide speculation in March that it was a girl after Kate, 31, accepted a baby gift saying: "Thank you, I will take that for my d..."

Bookmakers have had a field day cashing in on speculation of the baby's gender, possible names, and even hair color.

William Hill has a girl at favorite at 4-7 with the top names Alexandra, Charlotte, Elizabeth, Diana and Victoria. They are taking odds of 5-4 for a boy with George and James favored.

"The name will be traditional. This is a future monarch. You won't get a Princess Kylie or Prince Wayne," Little said.

With the popularity for royal family riding high in Britain and overseas after the royal wedding and last year's Diamond Jubilee celebrating Queen Elizabeth's 60 year reign, retailers are cashing in on the new arrival.

Stores are stocking "Born to Rule" sleepwear, palace shops are selling sleepsuits modeled on a guardsman's outfit, and Prince Charles is selling baby shoes from his country estate.

Celebrity jewellery designer Theo Fennell has created the most lavish baby gift so far - a bejeweled, 18ct white gold bracelet with a nappy cream holding charm for 10,000 pounds.