She was a princess, the daughter of King Leopold II of the Belgians, the wife of a prince, and a familiar figure in the court of the aged Emperor, Franz Joseph of Austria-Hungary.

Her lover was second lieutenant Gza Mattachich. Ten years younger than the princess, a dashing figure in his fitted tunic and shiny boots, he was an unknown, undistinguished, unmoneyed subaltern: a man of dubious origin and extravagant ambition.

Ahead of them both lay assignations, adultery, flight, the squandering of a fortune (not his; not hers either, as things worked out), a duel, imprisonment, bankruptcy, morphine, madness (or alleged madness).

And, as well, a real-life heroine – in the form of canteen-worker Maria Stger – who was no less ready than the princess and her soldier to risk all for love.

Beautifully handled, romantic, sumptuous, full of wit and a real treat to read, the action of Dan Jacobson’s All For Love moves from one end to the other of pre-First World War Europe.

Constantly fusing historical fact with fiction, it elevates three extraordinary characters from the footnotes of history and puts them, along with their few friends and many enemies, at the centre of a drama that is both comic and painful, and as astonishing as it is convincing.