Rome has had a Jewish community since the 2nd century BC, and from that time until the present its living conditions have varied widely according to its relations with the city's rulers. In 1555 Pope Paul IV Carafa established Rome's Ghetto Ebraico in the neighborhood marked off by the Portico d'Ottavia, the Tiber, and the Piazza dei Cenci. It measured only 200 yards by 250 yards. Jews were obligated to live there by law and the area quickly became Rome's most densely populated and least healthy. The laws were rescinded when Italy was unified in 1870 and the pope lost his political authority, but German troops tragically occupied Rome during World War II and in 1943 wrought havoc here. Today there are a few Judaica shops and kosher groceries, bakeries, and restaurants (especially on Via di Portico d'Ottavia), but the neighborhood mansions are now being renovated and much coveted by rich and stylish expats. The Museo Ebraico arranges tours of the Ghetto. The museum has exhibits detailing the millennial history of Rome's Jewish community.