Coronation.
The coronation.
Charles !
The cast of The Crowned King and Queen in Procession - 1902 includes: Queen Alexandra as herself King Edward VII as himself
When they become king or queen
The king
High King Peter, or Peter the Magnificent. Queen Susan the Gentle. King Edmund the Just. Queen Lucy the Valiant.
Queen Hedwig of Poland was crowned as a king because she wanted to underscore the fact that she was the reigning monarch. Queens were seldom reigning monarchs.
Synonyms for a ruling king or queen would be monarch, sovereign, or crowned head.
the coronation
Successor
William and Mary
Queen Victoria was crowned aged 19 and ruled for 64 years.