The Weight of the Crown by Fred M. White

Prince Peretori was a by no means unpopular figure with those who knew him both personally and by reputation. He had in him that strain of wild blood that seems peculiar to all the Balkan Peninsula, where so many extravagant things are done. In bygone days Peretori would have been a romantic figure. As it was, Western civilisation had gone far to spoil his character. Audacious deeds and elaborate practical jokes filled up the measure of his spare time. For some months under a pseudonym he was a prominent figure at a Vienna theatre. It was only when his identity became threatened that he had to abandon his latest fad.

But he was feeling deeply chagrined and mortified over his last escapade. It never occurred to him at the time that he was doing any real harm. The King of Asturia, his cousin, he had always disliked and despised; for the queen he had the highest admiration. And it looked as if he had done the latter an incalculable injury.