Today, he will make his first official visit to Madrid for bilateral talks with Spain's prime minister Mariano Rajoy before travelling to Paris for a working dinner with French president Francois Hollande.
He will also meet with German chancellor Angela Merkel later this week.
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There was something very striking about the pact, which implies the new agreement could remain in place even if the prime minister does not.
The royal will visit the site of the deadly attack at Manchester Arena as he remembers those killed and injured.
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