King's coronation: Which royals from Europe are attending and how are they related to Charles III?

The coronation of Britain's King Charles III will see the biggest gathering of European royalty since the funeral of Queen Elizabeth II in September last year. 

Historically, convention dictated that no other reigning royals would be in attendance at the coronation of a British monarch. But Charles and Camilla have extended invitations to their friends and relatives in royal families around Europe and the world -- monarchs and royals from Africa, Asia and the Middle East have arrived in London to take part in the ceremonies. 

You can follow our live coverage of the coronation service on Saturday here.

So which European royals are attending the coronation, and how are they related to the British royals? 

Here's our guide:

King Philippe and Queen Mathilde of Belgium are attending the coronation. Their eldest daughter, Princess Elisabeth, studies history and politics at Oxford University, and accompanied her father to a reception at Buckingham Palace on Friday evening, the night before the coronation. 

How are the British and Belgian royal families related? It's complicated, but: King Philippe's ancestor is King Leopold I, the first King of the Belgians, who was also Queen Victoria's uncle. And Queen Victoria was Charles III's great-great-great-grandmother.

Queen Margrethe II will be unable to attend as she is recovering from back surgery. Instead, her eldest son and heir Crown Prince Frederik and his wife Crown Princess Mary will be there. 

The Danish royal couple met at the 2000 Sydney Olympic Games and romance blossomed. 

Queen Margrethe II of Denmark is a distant relative of King Charles through their shared ancestry with Queen Victoria.

Queen Anne-Marie of Greece is attending the coronation with her son Crown Prince