EVEN VIEWED FROM just eight years away, the 20th century makes you wonder. What possessed us? Whence the epic, unstoppable bloodlust?

The questions arise not so much because of the world wars, but because of the second-tier orgies of slaughter and suffering that went on in their historical shadow. The Russian civil war was one; four years of frenzied butchery that terrorised Eurasia with barely a pause for breath after Versailles.

And the great rolling convulsion that seized China for 23 years, devouring tens of millions of innocents but leaving Mao triumphant, was another. This was a maelstrom of overlapping wars, famines, floods and generalised destruction fuelled by the greed of warlords, Japanese fascism, paranoid Chinese nationalism and overcooked Marxian ideology.

Through the chaos ran the fragile threads of countless individual stories, but few can have been more astonishing or, in the end, uplifting, than that of George Aylwin Hogg.

James MacManus, then a foreign correspondent for the Daily Telegraph, first heard about Hogg in an eavesdropped conversation at the British Embassy Club in Beijing in 1984. The account that he has pieced together since is of an Englishman abroad, but hardly of the cliché those words suggest.

Hogg had the prodigious stamina so often traced to the rainswept playing fields of English public schools, and he stood out in China for other obvious reasons, including his height, his hair, his “high nose” and the colour of his skin. But more than any of his compatriots who immersed themselves in war-torn China, he stands out for something else entirely: his goodness.

Thomas Keneally has noted (in his introduction to Schindler's Ark) how much harder it can be to write about the good than the bad. In Ocean Devil, MacManus answers the challenge as Hogg himself would have wished, by stripping his narrative of superfluous sentiment and letting his subject's extraordinary odyssey speak for itself.

That odyssey took the young Oxford graduate to Shanghai via the US and Japan in 1938. He had no fixed career plans and intended to stay in China for two weeks. He never left. Instead he drifted inland with the foreign press corps covering the Chinese retreat from Japan's invading army.

At first the elite foreign reporters of the era hold the spotlight, and little wonder: they included Gelhorn, Hemingway, Peter Fleming and a whole cadre of Americans annealed by the Spanish Civil War. Hogg was a hanger-on, stringing on and off for most of the big agencies and the appallingly stingy Manchester Guardian.

But as Hogg masters the reporter's craft and eventually takes up the post of headmaster of a boarding school for orphaned and abandoned boys deep in the hinterland, he moves effortlessly to the centre of the narrative.

Here is an alien creature drawn away from friends, family and comfort by his sense of adventure, then embedded in his new country by endless curiosity and a deep sense of duty.

It is no surprise that Hogg's story has now been made into a film. If the actor Jonathan Rhys Meyers has done him justice it will be the performance of his career.

Ocean Devil by James MacManus
Virago, £15.99; 241pp Buy the book

Times Recommends

• Superfreakonomics by Steven D Levitt and Stephen J Dubner
• The Times picks the 50 best paperbacks of 2009
• Vincent van Gogh’s letters show the soul of the artist