The son of Prince Harry and Meghan Markle is expected to be baptised later on Saturday.
The Archbishop of Canterbury will conduct the rite during a private ceremony.
Close family and friends will attend the christening, which will take place inside a private chapel at Windsor Castle.
However the Queen will not be there.
Archie Harrison Mountbatten-Windsor was born on May 6 this year.

Damascus cafe blast kills 5, wounds 16
Rebels in Indonesia's Papua kill American pilot, burn plane
Russian air strikes kill 10, injure more than 50 in Ukraine's Kyiv
Firefighters battle wildfire in southern France
US, Iran talks conclude in Doha, focused on Strait of Hormuz
Trump honours Theodore Roosevelt in North Dakota, debuts new Air Force One
Kenyan court charges 8 schoolgirls with fellow students' murder
At least 5 people killed in fire in Antwerp apartment block
