In all the best stories, the boy gets the girl and they live happily ever after. But the merger of the London Stock Exchange (LSE) and Deutsche Börse could be doomed by Ancient English folklore.

During the merger negotiations, the two exchanges borrowed codenames from the legend of King Arthur to ensure - unsuccessfully - that news of the merger didn't get out. We assume Lancelot, the handsome, powerful and virile warrior, was the LSE - perhaps even Gavin Casey himself. Gwynever, King Arthur's wife, was the most beautiful and fairest woman in all Christendom. Surely there's none fairer than the top boffins over at Deutsche. All the boys, including the strapping Lancelot, fell hopelessly in love with her and wanted to, um… 'merge' with her. But everyone knows that Lancelot never got the girl and, out of a sense of honour and duty, banished himself from Camelot.