The Queen and Duke of Edinburgh are to miss Prince Louis's christening, Buckingham Palace has confirmed.
The decision is understood not to have been taken on health grounds, and to have been mutually agreed by the Queen and the Cambridges some time ago.
The monarch, 92, has a busy week ahead, with high-profile celebrations in central London marking the centenary of the RAF on Tuesday, and a visit by US President Donald Trump in Windsor on Friday.
The Duke of Edinburgh, 97, has retired from public duties and has been enjoying his free time away from London.
Louis, the 11-week-old youngest son of the Duke and Duchess of Cambridge, is being baptised by the Archbishop of Canterbury on Monday afternoon in the Chapel Royal, St James's Palace in London.
His six godparents have been announced as: Nicholas van Cutsem; Guy Pelly; Harry Aubrey-Fletcher; The Lady Laura Meade; Mrs Robert Carter; and Miss Lucy Middleton.