As the Windsors prepare for Prince Louis’s christening, here is a look at what to expect from a royal baptism:

– They are usually private

Christenings for Windsor babies are conducted behind closed doors, except for Princess Eugenie’s.

Princess Eugenie's christening
The christening of Princess Eugenie of York (Martin Keene/PA)

She became the first royal baby to have a public christening, during morning service at the Church of St Mary Magdalene at Sandringham in 1990.

Photographs will be taken of Prince Louis on his big day though.

– The ceremony takes place soon after birth

Prince George was three months old and Princess Charlotte was only nine weeks at their christenings. Louis will be 11 weeks old.

Christening of Prince George of Cambridge
Three-month-old Prince George with his parents (John Stillwell/PA)

One of the longest waits for a christening was for Eugenie, who was nine months old.

– The godparents are announced on the morning of the christening

Rather than just three godparents – the minimum suggested by the Church of England – royal babies have a lot more.

George has seven, Charlotte has five, the Duke of Cambridge has six, the Queen had six and the Prince of Wales had eight.

– William and Kate usually opt for confidantes over royal relatives

Kate and William chose three close friends, a Spencer relative and a Middleton relative as Charlotte’s godparents but no members of the royal family.

Royal babies traditionally used to have kings and queens and other royals as godparents.

Charles’s godparents in 1948 included King George VI, Queen Mary, Princess Margaret, the King of Norway and Prince George of Greece.

The christening of Prince Charles – Buckingham Palace, London
Princess Elizabeth with baby Charles after his christening, with godparents Dowager Marchioness of Milford Haven, Queen Mary, Lady Brabourne, The Duke of Edinburgh (standing for Prince George of Greece), King George VI, David Bowes-Lyon, the Earl of Athlone (for the King of Norway) and Princess Margaret (PA)

– The Cambridges take inspiration from the past

At Charlotte’s christening, Prince George’s outfit was almost an exact copy of the red shorts and embroidered white shirt his father wore to meet baby Prince Harry for the first time.

Princess Charlotte's christening
The Duke and Duchess of Cambridge with Prince George and Princess Charlotte, in a pram, ahead of her christening (Chris Jackson/PA)

Charlotte was pushed to her christening in a vintage 1950s silver-wheeled Millson pram – once used for the Queen’s youngest children Prince Andrew and Prince Edward.

– The christening robe

Royal babies are christened in a replica of the intricate lace and satin christening gown made for Queen Victoria’s eldest daughter.

Christening of Prince George of Cambridge
Prince George in his christening robe (John Stillwell/PA)

It was created by the Queen’s dresser Angela Kelly.

The original Honiton lace and white satin robe, made in 1841, was last used in 2004 and is too delicate to be worn.

– Holy water

According to tradition, the water used for Louis’s christening will be holy water from the River Jordan, where it is said Jesus was baptised by John the Baptist.

– Lily font

Louis will also be christened using the ornate silver gilt Lily Font – part of the Crown Jewels.

The Lily Font
The Lily Font and silver ewer used at royal christenings (Anthony Devlin/PA)

It is decorated with lilies and ivy foliage around the rim, features three cherubs around the base, and the main bowl is a large lily bloom.

– Protecting the reputation of Queen Victoria’s family

The font was specially commissioned by Queen Victoria to prevent her children being tarnished by association with the illegitimate offspring of Charles II, who were all born out of wedlock and christened using the previous font, the Charles II Font.

– Cake for tea

Guests are likely to be served a slice of William and Kate’s wedding cake, just as they were after George and Charlotte’s christening.

William and Kate's wedding cake
Chef Fiona Cairns with William and Kate’s wedding cake (John Stillwell/PA)

It was designed by Fiona Cairns and made from 17 individual fruit cakes, with eight tiers. They saved a tier for their future children’s baptisms.

– Extravagance used to be the order of the day

Victoria staged a lavish celebration at Windsor for the christening of her son, the future Edward VII, in 1842.

She wore her Sovereign of the Garter robes and a diamond tiara and organised a long day of grand events including a state banquet and a christening cake over 8ft in diameter.

– Timings can be tricky

According to biographer Andrew Morton, Diana, Princess of Wales complained she was not consulted over the best time for Prince William’s christening in 1982.

“Nobody asked me when it was suitable for William. 11 o’clock couldn’t have been worse,” she said.

Prince William's christening – Buckingham Palace
The royal family gather for Prince William’s baptism (PA)

– There have been dramas

Queen Victoria’s mother the Duchess of Kent broke down sobbing during her daughter’s christening in 1819 when a cantankerous Prince Regent refused to allow her to name her daughter Georgiana and insisted she be called Alexandrina Victoria instead.

– And guests have not always been well behaved

At the christening of Queen Victoria’s daughter, Princess Alice, in 1843, the Queen’s uncle, Ernest, King of Hanover, arrived late, behaved rudely and made a public fuss in a dispute with Victoria over the ownership of certain royal jewels.