WITH the arrival of a royal baby comes the age-old custom of placing a proclamation of royal birth behind the iron railings of Buckingham Palace.

Even in the fast Twitter-paced age, Palace aides had previously signified that the tradition would be adhered to for the Duke and Duchess of Cambridge’s firstborn.

The brief bulletin, on headed Palace notepaper, confirmed the sex of the baby but gave little else away other than that the baby had been “safely delivered” and his weight.

It used to be hand-written but is now mostly typed and then signed by royal doctors.

Placed in a foolscap sized dark wooden frame, it is set on an ornate easel behind the railings, just to the side of the front gates of the Queen’s London home for members of the public to read.

When the Queen gave birth to Prince Andrew in 1960, some 2,000 people crowded around the railings as the official confirmation announcing the birth of a son - the Queen’s third child - was fixed to the gates by Stanley Williams, the then Superintendent of the Palace.

The names given to royal babies are not usually revealed straight away and the public is often left guessing for several days.

When Princess Beatrice was born in 1988, it was two weeks before her name was known.

When William was born in 1982, his parents the Prince and Princess of Wales waited seven days before deciding upon and announcing his name.

The Prince of Wales’s name, however, remained a mystery for an entire month and was only declared ahead of his christening in the Music Room of Buckingham Palace in December 1948.

Royal births are usually celebrated with a Royal Salute of 41 guns. The Prince's birth was also marked by a three hour peal at Westminster Abbey.

They are registered in the normal way, although the Home Secretary is required to notify certain officials including the Lord Mayor of London, the Governors of Northern Ireland, the Channel Islands and the Isle of Man.

The Queen’s top aide, her Private Secretary Sir Christopher Geidt, informs Governor Generals overseas.