London: Britain's Prince Louis of Cambridge, the baby son of Prince William and his wife, Kate, is to be christened on Monday but Queen Elizabeth II will not be in attendance, Kensington Palace said.
Queen Elizabeth, 92, and her 97-year-old husband, Prince Philip, attended the christenings of Louis' older siblings Prince George and Princess Charlotte.
But the decision for them not to attend Louis' baptism at St. James's Palace in London was understood to have been mutually agreed by the monarch and the Duke and Duchess of Cambridge some time ago and was not health-related.
They will return to London from the monarch's private Sandringham estate in eastern England on Monday.
Archbishop of Canterbury Justin Welby, the spiritual leader of the world's Anglicans, will lead the service in the Chapel Royal at St James's Palace.
Welby, who will baptise the baby by pouring holy water from the River Jordan over his head, said the event would be "very nerve-wracking" but "a great privilege".
Louis is fifth in the line of succession to the British throne after his grandfather Prince Charles, his father William and his older siblings George and Charlotte.
He is also one of Queen Elizabeth's seven great-grandchildren.
From the royal family, the baptism will be attended by William's father Charles and his wife Camilla; and William's brother Prince Harry and his new wife Meghan, who married in Windsor Castle in May.
From the duchess's side, Kate's parents, Michael and Carole; brother, James; sister, Pippa; and her husband, James Matthews were to attend.
The six godparents and their spouses were also due to attend.
The godparents are all friends or family of William and Kate.
They include Guy Pelly, once dubbed the "court jester" to William and Harry for his wild ways that were often cited as a bad influence on the brothers in their youth, running their favourite drinking haunts.
Louis' other godparents are: Nicholas van Cutsem, whose family is close to the royals; William's school pal Harry Aubrey-Fletcher; Laura Meade, who is married to William's close friend James Meade; Kate's schoolfriend Hannah Carter; and the duchess's cousin Lucy Middleton.
Welby will use the Lily Font, commissioned by queen Victoria for the baptism of her first child in 1841.
Louis will wear the replica of the royal christening robe, first used in 2008. The original, retired in order to preserve it, was worn for all royal baptisms since 1841.
William and Kate were to host a private tea afterwards. As after George and Charlotte's baptisms, guests will be served slices of the duke and duchess's wedding cake.
Louis was born on April 23 – St. George's Day, England's national day – at St Mary's Hospital in central London weighing 3.8 kilogrammes.