LONDON - Britain's Prince William and his wife Kate on Friday registered the birth of their son George, who was born on July 22 in a blaze of global publicity and is third in line to the British throne.

Known officially as the Duke and Duchess of Cambridge, the new parents completed the bureaucratic step at Kensington Palace, their London residence, the palace said in a statement.

A copy of the birth register for Prince George of Cambridge is seen at Westminster Register Office in London August 2, 2013. Britain's Prince William and his wife Kate on Friday registered the birth of their son George, who was born on July 22 in a blaze of global publicity and is third in line to the British throne.[Photo/Agencies]

Under the law, all births in England must be registered within 42 days of the child being born.

Prince William signed the birth register, witnessed by a registrar from Westminster Register Office.

The palace released a photograph of the infant prince's birth certificate, which mixed the mundane and the monarchic.

Hand-written on the same sober form used to register the births of ordinary British babies, the document is entitled "Birth" and the entry number on the register is 207.

The names and occupations entered on the form are anything but ordinary, however.

The baby's name is recorded as His Royal Highness Prince George Alexander Louis of Cambridge.

The parents' names are recorded as His Royal Highness Prince William Arthur Philip Louis Duke of Cambridge and Catherine Elizabeth Her Royal Highness the Duchess of Cambridge.

The father's occupation is "prince of the United Kingdom" while the mother's is "princess of the United Kingdom".

Prince William is a Royal Air Force search and rescue helicopter pilot, but the form makes no mention of that.

Britain's Prince William holds his baby son outside the Lindo Wing of St Mary's Hospital before leaving with Catherine, Duchess of Cambridge, in central London July 23, 2013.[Photo/Agencies]