Complex sentence: Güyük died on the way, in what is now Xinjiang; he had succumbed at about the age of forty-two to the combined effects of alcoholism and gout, although he may have been poisoned.
Split into simpler sentences: Güyük died on the way, in what is now Xinjiang at about the age of forty-two. C. P. Atwood "Encyclopedia of Mongolia and the Mongol Empire", p.213, he may have succumbed to the combined effects of alcoholism and gout or been poisoned.