Frederiksted is both a town and one of the two administrative districts of St. Croix, U.S. Virgin Islands. It is a grid-planned city, designed by surveyor Jens Beckfor, originally to 14×14 blocks but built 7×7 to enhance the island commerce in the 1700s. Fewer than 1,000 people live in Frederiksted proper, but nearly 10,000 live on the greater western side of the island. Christiansted is about 30 years older, but commerce was limited by its natural, shallow protective reef. Frederiksted was built in the leeward side of the island for calm seas and a naturally deep port. It is home to Fort Frederik, constructed to protect the town from pirate raids and attacks from rival imperialist nations and named after Frederick V of Denmark, who purchased the Danish West Indies in 1754.