We don't get to learn our hero's name until quite near the end of the story, but he's an academically brilliant Turkish man in his thirties with a good income and no shortage of employment prospects.

He's doing well for himself. However, what he didn't expect was to be informed by an enigmatic trio of strangers that he is the emperor-in-exile of the Byzantine Empire, which may be defunct but still brings with it a prestigious title and a handsome salary. In future, he will be known as Constantine XV, after he's performed a few tasks to prove he deserves the honour.

This secret cabal has existed for centuries, keeping tabs on the bloodline of Constantine XI (who escaped the siege of Constantinople, whatever historians might say). That should be the cue for a ripping, far-fetched yarn in the manner of The Da Vinci Code.

However, instead of striving to create tension and urgency, Altun takes a different path, putting his protagonist on a journey that's largely free from peril and almost languid in its pace. The tasks he is set are absurdly simple for a man with his eye for antiquities and, in between them, he has the resources to hop from country to country to follow up his own theories.

As a white-knuckle conspiracy thriller, The Sultan Of Byzantium is tepid indeed, so that was clearly not the point. The story Altun is more eager to tell is that of his hero's growth as a person: coming to terms with the truth about his family, accepting the responsibilities of adulthood, finding love and reaching a deeper understanding of the ancient culture which has fascinated him all his life.

Self-confessed bibliophile Altun has written a love letter to a civilisation long gone, endeavouring to sow the seeds of fascination in his readers with an empire that lasted 1100 years.

Frankly, our well-off, indulged, intellectual narrator is a hard person to care about. But if Altun's purpose was to send readers scurrying off to investigate the glories of Byzantium for themselves – its unique and distinctive culture, its eventful and often violent history – he's done an exemplary job.

Selçuk Altun, Telegram Books, £8.99

THE SULTAN OF BYZANTIUM