For the milestone, the new prince will wear the same exact gown that his brother and sister donned. An identical christening gown was also worn by the Prince of Wales, Prince Harry and Prince William at their own christenings.
Since Queen Victoria commissioned the gown's creation for her daughter Princess Victoria in 1841, it's been worn by 62 royal babies. After 160 years, it became so fragile that the royals were forced to retire it in 2004. Consequently, an identical gown was made.
Princess Charlotte was the seventh royal baby to wear this version of the gown, at her own christening in 2015. For more on the upcoming ceremony, watch the video above!
RELATED: Royal family residences
Royal family residences
Royal family residences
We'll start at Buckingham Palace, the Queen's London home. Situated by St. James's Park, Buckingham Palace has been the monarch's official London residence since 1837. It has 775 rooms, including 52 bedrooms, 188 staff bedrooms, 92 offices, and 78 bathrooms.
The Queen and the Duke of Edinburgh live here, along with The Duke of York, and the Earl and Countess of Wessex.
Highlights at Buckingham Palace include the Changing of the Guard ceremony, which takes place most days at 11:00 a.m., and the State Rooms that are open to the public every summer. Plus, there's a rumor that the ghost of a monk in a brown cloak haunts the back terrace!
Windsor Castle, situated just outside London, is the Queen's weekend retreat. It's the oldest and largest occupied castle in the world, built by William the Conqueror in the 11th century. Over 39 monarchs have used Windsor Castle as their residence. St George's Chapel is part of the castle and is the venue for the wedding of Prince Harry and Meghan Markle in May 2018.
The castle is open all year round—it has a world-famous Royal dollhouse!—and there are also talks, performances, and activities for kids.
In 1992, a fire at the castle caused over $50,000,000 in damage.
Sandringham House in Norfolk is one of the Queen's private residences. It was brought into the family in 1862 by the future Edward VII, although a fire in 1891 destroyed much of the original building. It's been passed down through the family into the Queen's ownership. The house itself stands within nearly 20,000 acres, with 60 acres of gardens. The rest is a park and uncultivated land, which is freely open to the public every day of the year.
The British royal family spends Christmas at Sandringham, traditionally walking to church on Christmas morning and meeting the local people.
Anmer Hall, a private residence of the Duke and Duchess of Cambridge, is also part of the Sandringham estate.
Who wouldn't love to live in their own Scottish castle? Balmoral Castle is another of the Queen's private residences, situated in Aberdeenshire, Scotland. Bought by Prince Albert as a gift for Queen Victoria in 1852, they built a new castle before demolishing the old one. Other royal residences on the grounds are: Birkhall (a residence of the Prince of Wales and Duchess of Cornwall), Craigowan Lodge, and Delnadamph Lodge.
There are vacation cottages to rent on the estate, which also boasts a golf course and offers Landrover safaris of the surrounding countryside. But watch out for the ghost of John Brown, Queen Victoria's servant, who is said to roam the grounds at night wearing a kilt. (Don't miss these other royal ghosts still haunting Britain today!)
Owned by the Crown, Clarence House was home to Queen Elizabeth The Queen Mother for more 50 years. Designed by John Nash in 1825-27, it was built for George III's son Clarence, hence its name. But it's since undergone extensive remodeling to make it suitable for modern living.
Clarence House is attached to St. James's Palace and the two residences share the same gardens. Although other members of the British royal family visit, Clarence House is the official London residence of the Prince of Wales.
Originally bought by William III in 1689, Kensington Palace was the main residence for the British royal family until Queen Victoria moved into Buckingham Palace. Queen Victoria was born and grew up here, and it was also Princess Diana's home.
Kensington Palace belongs to the Crown Estate, and is currently the official home of the Duke and Duchess of Cambridge (along with Prince George and Princess Charlotte of course!), as well as Prince Harry. Historic parts of the building are open to the public, and the Royal Ceremonial Dress Collection is housed here.
St. James's Palace
St James's Palace also belongs to the Crown, and has been a residence for the British royal family for more than 300 years. It was originally built by Henry VIII in 1531-36 and has been used continuously since then. Queen Victoria's wedding took place here.
On the death of a monarch, the Accession Council meets at St. James's Palace, and the official announcement of the new sovereign is also made from here. It's currently home to Princesses Beatrice and Eugenie, The Duke and Duchess of Gloucester, Prince and Princess Michael of Kent and Princess Alexandra, when she's in London. The Princess Royal and her husband Sir Timothy Laurence also live here—their country residence is Gatcombe Park.
St James's Palace also hosts more than 100 charity events every year.
Palace of Holyrood House
Balmoral Castle is the Queen's private residence, but when she's in Scotland on an official visit, she stays at the Palace of Holyrood House. Situated at the end of Edinburgh's famous Royal Mile, it was founded first as a monastery in 1128. Rebuilt as a palace by James IV in 1501, this building has been the official residence of the monarchy in Scotland ever since.
Mary Queen of Scots lived most of her life here and it was the scene of the famous murder of David Rizzio, her private secretary, in her bedroom. Seven months pregnant, Mary witnessed the murder, and it's said that to this day, the blood stains can't be removed from the floor.
The Queen hosts around 4,000 visitors during the annual Holyrood Week in June, and the palace is open to the public all year round.
When visiting Northern Ireland, the British royal family stays at Hillsborough Castle in County Down. It's also the residence of the Secretary of State for Northern Ireland. But its name is misleading! It's actually a Georgian country house built in the 18th century—the British government only bought it in 1922. Hillsborough Castle was the venue for several important negotiations during The Troubles, and it was here that the historic Anglo-Irish Agreement was signed, leading eventually to peace in Northern Ireland after decades of conflict.
Prince Charles is also Duke of Cornwall, so properties owned by the Duchy of Cornwall are currently used by him. He first moved into Highgrove House in Gloucestershire in 1980, and has transformed the house and gardens into a model of sustainability. The gardens are open to the public on selected dates.
There's a reed bed sewage system, a collection of rare trees and plants, and also a heritage seed project on site to preserve rare seeds for future generations. There are solar lights, energy-saving bulbs, a composting system, and the house is warmed using heat pumps.
The Duchy of Cornwall also owns two other properties for Prince Charles to use. Tamarisk is on the beautiful island of St. Mary's, one of the five inhabited islands in the Isles of Scilly. There are over 200 islands in the Scillies chain altogether, and the Duchy of Cornwall owns most of the land and around one-third of the houses. Tamarisk House is Prince Charles' official residence when he's in the Scillies, and when in Wales, the Prince of Wales' residence is Llwynywermod in Carmarthenshire.
The Scilly Isles are famous for their natural beauty and rare bird life. The Isles of Scilly Wildlife Trust manages the wildlife on the island. Their annual rent to the Duchy of Cornwall is one daffodil!
Birkhall, situated within the grounds of Balmoral Castle, is a private residence of the Prince of Wales. Built in 1715, it became Queen Victoria's when Prince Albert gifted her the Balmoral estate in 1849. It's since been passed through the family to the Queen Mother and then Queen Elizabeth in 2002.
The estate is famous for its beautiful scenery and country walks, as well as fishing and hunting. It's a popular holiday haunt for Prince Charles and the Duchess of Cornwall.
Within the grounds, there's a beautiful thatched playhouse, built for Princess Elizabeth and Princess Margaret Rose when they were small, and since enjoyed by all the royal children.
Royal Lodge Windsor
Royal Lodge, Windsor (situated in Windsor Great Park), is leased by the Duke of York from the Crown, and was also home to the Princesses Beatrice and Eugenie before they moved into St. James's Palace. This property also has a playhouse, built for Queen Elizabeth when she was six years old. Created by Welsh craftsmen, and given a Welsh name (Y Bwthyn Bach or The Little Cottage), the house has electricity and running water, as well as a gas stove.
Wren House is part of Kensington Palace. It stands a little to the north of the main palace and overlooks a beautiful walled garden. It's currently home to the Duke and Duchess of Kent.
Bagshot Park was built within Windsor Great Park, and is leased from the Crown. It was built in 1879 as the main residence of Prince Arthur, Queen Victoria's son, and the design was influenced by Indian culture. Queen Victoria was also Empress of India at the time. Since 1998, the Earl of Wessex has leased Bagshot Park and has overseen extensive renovations on the property. It's now the official residence of the Earl and Countess of Wessex.
Thatched House Lodge
Thatched House Lodge, in Richmond Park, is the residence of the Queen's cousin, Princess Alexandra. It's situated in one of the royal parks famous for its beautiful surroundings including wild deer, like those in this picture, taken in Richmond Park. Built in the 17th century, it also has a thatched summerhouse, a gardener's cottage, stables, and gardens.