The County of Carnarvon covers the full extent of Kangaroo Island and “all islands adjacent thereto.”
History
The County of Carnarvon was gazetted in 1874 in response to the demand for agricultural land on Kangaroo Island. The county was proclaimed by Anthony Musgrave, the ninth Governor of South Australia on 13 August 1874 along with the first of its constituent hundreds, the Hundred of Dudley. The country was named after Henry Herbert, 4th Earl of Caernarfon, Wales who served two terms as the British Secretary of State for the Colonies. The following twelve hundreds were proclaimed within the County between the years 1874 and 1960 - Dudley in 1874, Menzies in 1878, Haines in 1883, Cassini in 1884, MacGillivray in 1906, Seddon in 1908, Newland in 1909, Duncan in 1909, Ritchie in 1909, McDonald in 1910, Gosse in 1931, and Borda in 1960. A thirteenth hundred was proposed during the 1930s but was never proclaimed - the Hundred of Baudin.
The hundreds located within the County of Carnarvon are laid out as follows - Borda, Gosse, Duncan, Cassini and Menzies overlooking the north coast of the island, MacDonald, Ritchie, Newland, Seddon and MacGillivray overlooking the south coast of the island, with Haines occupying the full extent of the island south of Nepean Bay and Dudley occupying the full extent of the Dudley Peninsula.
Hundred of Borda
The Hundred of Borda ( was proclaimed on 4 February 1960 and was named after the headland, Cape Borda. Its extent includes the locality of Cape Borda and part of Flinders Chase.
Hundred of Cassini
The Hundred of Cassini was proclaimed on 8 May 1884. It covers an area of and was named after the headland, Cape Cassini. Its extent includes most of the locality of Cassini and a small section of the locality of Duncan.
The Hundred of Duncan was proclaimed on 9 December 1909. It covers an area of and was named after John Duncan, a South Australian politician and pastoralist. Its extent includes the localities of Middle River and Stokes Bay, most of the locality of Duncan, and parts of the localities of Gosse, Newland, Seddon and Western River.
Hundred of Gosse
The Hundred of Gosse was proclaimed on 25 June 1931. It covers an area of and was named after William Christie Gosse, an explorer and a former Deputy Surveyor-General in South Australia. Its extent includes the locality of De Mole River, most of the locality of Western River, and parts of the localities of Gosse and Flinders Chase.
Hundred of Haines
The Hundred of Haines was proclaimed on 10 May 1883. It covers an area of and was named after William Haines, a South Australian politician. Its extent includes the localities of American River, Ballast Head, D'Estrees Bay, Haines, Muston and nearly all of Nepean Bay.
Hundred of MacGillivray
The Hundred of MacGillivray was proclaimed on 20 December 1906. It originally covered an area of which was expanded in 1945 to. It was named after Ivor MacGillivray, a South Australian politician. Its extent includes nearly all of the localities of Macgillivray and Birchmore and parts of Kohinoor and Menzies.
The Hundred of Newland was proclaimed on 4 March 1909. It covers an area of and was named after John Newlands, a South Australian politician. Its extent includes part of the localities of Gosse, Karatta, Newland, Seddon, Stun'Sail Boom and Vivonne Bay.
Hundred of Ritchie
The Hundred of Ritchie was proclaimed on 9 December 1909. It covers an area of and was named after George Ritchie, a South Australian politician. Its extent includes parts of the localities of Gosse, Karatta and Stun'Sail Boom.
Hundred of Seddon
The Hundred of Seddon was proclaimed on 31 January 1908. It covers an area of and was named after Richard Seddon, a former Prime Minister of New Zealand. Its extent includes the localities of Parndana and Seal Bay, most of the locality of Seddon, and parts of the localities of Cassini, Duncan, Kohinoor, MacGillivray, Newland and Vivonne Bay.