Original sentence: Emperor Frederick I Barbarossa invaded the Italian peninsula in 1185, briefly ending the independence of the young republic.Florence prospered in the 12th century, with extensive trade to foreign countries providing a platform for demographic growth of the city.The Margraves of Tuscany again had possession of the city.The city built its first bridge over the Arno in 1128.The city was home to several towers and many churches.When the incumbent Holy Roman Emperor Henry VI died in 1197, the Florentines capitalised on the event, and they re-secured the city’s independence from the Marquisate of Tuscany
Edited sentence: Florence prospered in the 12th century, trading extensively with foreign countries.The Florentines re-asserted their independance when the incumbent Holy Roman Emperor Henry VI died in 1197.The Margraves of Tuscany re-acquired Florence and its townlads.The growth of Florence's population mirrored the rate of construction, many churches and palazzos were built.This prosperity was shattered when Emperor Frederick I Barbarossa invaded the Italian peninsula in 1185.This, in turn, provided a platform for demographic growth of the city