In a newsletter sent round a City of London firm, the lawyer said he had a “eureka moment” when he was “leaving a Scandinavian port on the Valerian Sea in the peak of winter [… and] saw the ice melting before my eyes”.

There is no such thing as the “Valerian Sea”, which colleagues suggested could have been an inadvertent reference to the Valyrians in hit TV show Game of Thrones, according to Legal Cheek.

The mistake could also be blamed on the big-budget sci-fi movie Valerian and the City of a Thousand Planets, which was released in 2017.