Complex sentence: After suffering from the effects of plague and fire in the 18th century, the city underwent a period of redevelopment which included the prestigious district of Frederiksstaden and cultural institutions such as the Royal Theatre and the Royal Academy of Fine Arts.
Split into simpler sentences: After suffering from the effects of plague and fire in the 18th century, the city underwent a period of redevelopment. This included construction of the prestigious district of Frederiksstaden and founding of such cultural institutions as the Royal Theatre and the Royal Academy of Fine Arts.