Prince Harry is 'mindful' not to upstage the King and keeps his diary clear during Charles's nine-day Caribbean tour

Prince Harry's choice to keep his schedule free during King Charles's nine-day Caribbean tour follows two earlier clashes that drew scrutiny, among them an appearance in Nottingham on the same day the King and Queen opened the Welsh Parliament. He is said to be careful not to overshadow his father or Prince William.

Half term is being spent with their two children — Archie, aged seven, and Lilibet, aged five — though Charles's tour is an additional reason the couple have kept their calendar clear.

Because the Sussexes operate outside the royals' formal diary-coordination system, known as 'the grid', questions remain about how future conflicts will be handled.

The couple are understood to have at least one joint public engagement lined up before the year is out.