Sydney is the southeastern island of the Phoenix Group. It lies 267 nautical miles south of the equator, 600 miles north of Pago Pago, and 60 miles east of Hull Island. With the last three islands it forms, a kit-shape, like the Southern Cross, the upright (Sydney to Enderbury) measuring 82 miles, with Phoenix and Birnie on the two sides, each 55 miles away.

Sydney Island might be described as a triangle with rounded corners, the base being about 2 miles, east and west, and each side about 1.3/4 miles. In the centre is a circular, very salty lagoon, about a mile in diameter and  up to 15 or 18 feet deep, without channel to the sea, and choked with small islets and shoals. At the southeast corner, an area where guano was dug 55 years ago, became a series of small, only slightly brackish ponds, which now have all but dried up.

The island is surrounded by a fringing reef, about 50 yards wide, behind which to a height of 15 or 20 feet rises a steep beach, partly sandy and partly covered with sandstone slabs and coral rubble. There is good anchorage on the west side, about 200 yards off the reef, in 10 to 14 fathoms, marked by a beacon on shore. Landing is not easy, and at times dangerous.

Behind the beach crest the land slopes gradually toward the lagoon. The western side has been planted to coconut palms, which form good groves, up to 70 feet high (80 to 90 feet above sea level). On the northeast side there is a dense, in places impenetrable, thicket of low forest, 15 to 20 feet high. Near the former ponds on the southeast, a small grove of coconut palms was planted, beginning about 1904. On the north and south sides of the lagoon there is open scrub forest. This is made up principally of Tournefortia, Pisonia, Morinda, Cordia, Guettarda, and Scaevola, with the usual low herbs, shrubs, and vines, found on the treeless island. 

The bird life is similar to that on the other islands, but less abundant. ducks used to be seen on the ponds, but now both are gone. Domestic pigs have run wild. There are the usual rats, lizards, and hermit crabs. Insects are abundant and of some variety, including a blue and white butterfly, several kinds of moths, dragonflies, ants, flies, leafhoppers, bugs, beetles, wasps, and spiders. There were formerly no mosquitoes, but these are said to have arrived on a ship from Tahiti about 1884.

Salt water has seeped into the lagoon, which stands a foot or so below the surrounding sea level, and has evaporated, leaving its salt behind, until this concentrated brine will no longer support marine life. Fish and mollusks formerly were abundant in the lagoon.

A great variety of marine life inhabits the fringing reef. Fish at Sydney have the reputation of being poisonous; but this applies only to some of the reef species, those which feed on seaweeds; the rest are excellent eating.

A most interesting feature of Sydney Islands found in the ancient ruins, which tell of Polynesian visitors of long ago. Hidden among the thickets, along the N.W. and N.E. sides are a dozen or more platforms and enclosures of sandstone slabs. From a study of these, K.P. Emory, Bishop Museum ethnologist, concludes that there were at least two groups of early visitors. One built a marae or shrine typical of Eastern Polynesia. Another group built platforms which suggest that they came from Micronesia. There was a fish pond in the lagoon, several wells, and pits which might have been used for cooking.

Sydney was discovered and named in 1823 by Captain Emment. While searching for it, the U.S. Exploring Expedition's ship Vincennes "discovered" Hull Island, August 26, 1840. On shore they found a sick Frenchman and 11 Tahitians, who informed them that Sydney Island lay 60 miles to the east. Stormy weather and strong currents prevented them from finding the island.

Sydney was among the islands claimed by American guano interests, but apparently they made no use of the island. About 1882 or 1883 John T. Arundel obtained a lease to it from Her Britannic Majesty. The Friend, for September 1883 gives notice to this. For possible guano-collecting ships it notes that the prevailing winds are from the east by north to east by south, regular from April to December. Captain Mann was the manager. "Guano will be brought alongside within reach of ship's tackles in boats provided by the shippers. It is shipped in bags, which are to be returned when empty."

Guano digging continued during 1884-5. There was a tram line around the north side of the lagoon, so well made that the roadbed forms an excellent level path today. Another short line ran from S.E. guano digging to a stone pier on the lagoon. Her marks indicate that the water level has dropped two feet during the 50 years. The camp and landing was then, as now, on the west end. Shipping guano was very difficult, due to the bad landing. The ship Lorenzo was wrecked while loading, and perhaps others suffered a similar fate.

The British flag was raised and protectorate declared, June 26, 18889. The island was used by Lever Brothers about 1905. In 1916 it was leased for 87 years to Captain Allen, representing the Samoan Shipping and Trading Co. They employed up to 16 natives to cut and dry copra and plant coconut palms. When Sydney was visited in March 21-23, 1924, there were 11 Samoans and Ellice Islanders in charge of Charles Jennings.

After the death of Captain Allen, 1925, Burns, Philp Co., took over the lease. With recently awakened interest in the central Pacific, the island was visited in January, 1937, by H.M.S. Leith (Captain L.C.P. Tudway, R.N.) and claim was reasserted in the name of King George VI.

The same year the rights of Burns, Philp Co., were bought out, and the island was made part of the Gilbert and Ellice Islands Colony, where Administrative Officer visited Sydney on H.M.C.S. Nimanoa in October, 1937.

Villages in the Gilbert and Ellice Groups were becoming crowded, and here was an island in need of inhabitants. So in the fall of 1933, a colony of natives was taken to Sydney. The village now numbers 130 persons, with native magistrate, radio operator, and energetic supervisor of public works and acting administrator, Kima Jack Pedro, Tokelau-Caucasian, brother of Mrs. Alexander Jennings, wife of the owner of Swains Island.

A model village has been built; cement cistern, with a capacity of 31,000 gallons, constructed; and 15 wells developed. Unfortunately drought in 1939 made the cistern nearly dry, and the wells go brackish; but rains improved conditions. Each man and woman has been given 50 coconut palms, to use as food or to make copra, and each child, two unplanted sections, each 150 feet square. So popular has been this experiment in native habilitation that two men and a woman even travelled across from the Gilberts, against wind and current in a small canoe. The Gilbertese (Kiribati) name for the island is Manra.