Complex sentence: Suffering from an unhappy love affair with Fanny Brawne, which perhaps further weakened his health, John Keats died at 25 of tuberculosis in 1821, and is buried in Rome, a city that continued to fascinate and inspire Andersen long after his first visit in 1833.
Split into simpler sentences: Suffering from an unhappy love story with Fanny Brawne, which perhaps further weakened his health, John Keats died of TB in 1821, only 25 years old. He is buried in Rome, a city that continued to fascinate and inspire Hans Christian Andersen long after his first visit in 1833.