The coronation of George VI

The video captures the grandeur of a coronation, unmatched by Hollywood's lavish productions. It symbolizes the unity of a modern people occupying a significant portion of the Earth's surface, featuring notable figures like Ramsay MacDonald, Stanley Baldwin, and Mackenzie King.

What fraction of the Earth's habitable surface is occupied by the modern people referred to in the text?

Who are the notable figures mentioned in the opening procession?