 The town's first significant defenses were likely erected due to commercial interests, following the temporary seizure of St. John's by the Dutch admiral Michiel de Ruyter in June 1665.The inhabitants fended off a second Dutch attack in 1673, when it was defended by Christopher Martin, an English merchant captain.Martin landed six cannons from his vessel, the "Elias Andrews", and constructed an earthen breastwork and battery near Chain Rock commanding the Narrows leading into the harbour.