Task: Question Generation
Input (English): Passage: The Bishop of Rome, called the Pope, was important since the early days of Christianity because of the martyrdom of both the apostles Simon Peter and Paul of Tarsus there. The Bishops of Rome were also seen (and still are seen by Catholics) as the successors of Peter, who is considered the first Bishop of Rome. The city thus became of increasing importance as the centre of the Catholic Church. After the Decline of the Roman Empire in 476 AD, Rome was first under the control of Odoacer and then became part of the Ostrogothic Kingdom before returning to Byzantine Empire control after the Gothic War (535-554), which devastated the city. Its population declined from more than a million in 210 AD to 500,000 in 273 to 35,000 after the Gothic War (535-554), reducing the sprawling city to groups of inhabited buildings interspersed among large areas of ruins, vegetation, vineyards and market gardens. It is generally thought the population of the city until 300 A.D. was 1 million (estimates range from 2 million to 750,000)  declining to 750-800,000 in 400 A.D., 450-500,000 in 450 A.D. and down to 80-100,000 in 500 A.D. (though it may have been twice this), Rome in Late Antiquity, Bernard Lancon, 2001, pp. 14, 115-119; Rome Profile of a City, Richard Krautheimer, 2000, pp. 4, 65.
Output (English): What comprised the city, other than inhabited buildings?