In 1669, fears of an Ottoman attack rose after the fall of Candia, and a new line of fortifications was proposed to encircle both the Birgu and Senglea land fronts, as well as the unfinished Santa Margherita Lines. The new line was named the Cottonera Lines after the reigning Grand Master, Nicolas Cotoner. It was designed by the Italian engineer Antonio Maurizio Valperga, who also modified the Floriana Lines and some other fortifications of the Grand Harbour. The Cottonera Lines were meant to accommodate up to 40,000 people and their animals within their circumference.