LONDON - Prince Louis, the third child of Britain's Prince William and wife Kate, has been christened at a small, private ceremony overseen by the Archbishop of Canterbury on Monday, without the Queen and Duke of Edinburgh attending.

Louis, the fifth in line to the British throne who was born on April 23, was christened at The Chapel Royal of St James's Palace in central London.

However, his great-grandmother the queen and her husband Prince Philip were not among the guests, Kensington Palace said.

A royal source said it had been agreed some time ago that the 92-year-old queen would not attend the small, family affair and her absence was not due to any health issues.

Elizabeth, the world's oldest and longest-reigning living monarch, did miss a special service last month because she was feeling "under the weather" but has carried out a number of public engagements since then.

The monarch was due to return to London on Monday ahead of a busy schedule of events including a meeting with US President Donald Trump on Friday at her Windsor Castle home.