Interpretation of the Dieppe Maps on the Harleian Mappemonde, as illustrated in Ernest Favenc, The history of Australian exploration from 1788 to 1888,'' London & Sydney, Griffith, Farran, Okeden & Welsh, Turner & Henderson, 1888 The central plank of the theory of Portuguese discovery of Australia suggests the continent called
Jave la Grande, which uniquely appears on a series of 16th-century French world maps, the
Dieppe school of maps, represents Australia. Speaking in 1982, Kenneth McIntyre described the Dieppe maps as "the only evidence of Portuguese discovery of Eastern Australia". He stressed this to point out "that the
Mahogany Ship, and the
Geelong Keys, and other things of that sort, are not part of the proof that the Portuguese discovered Australia. It is the other way around. The Dieppe maps prove (sic) that the Portuguese discovered Australia, and this throws a fierce bright light on our mysteries such as the Mahogany Ship". Later writers on the same topic take the same approach of concentrating primarily on "Jave la Grande" as it appears in the Dieppe maps, including Fitzgerald, McKiggan and most recently, Peter Trickett. Critics of the theory of Portuguese discovery of Australia, including A. Ariel, M. Pearson, W. A. R. Richardson, Gayle K. Brunelle and Robert J. King also concentrate on the "Jave la Grande" landmass of the Dieppe maps (see below). W. A. R. Richardson argues that Jave la Grande as it appears on the Dieppe world maps is at least partly based on Portuguese sources that no longer exist. McIntyre's own theory about distortion of the maps and the calculations used to correct the maps has also been challenged. Both Lawrence Fitzgerald and Peter Trickett argue Jave la Grande is based on Portuguese
sea charts, now lost, which the mapmakers of Dieppe misaligned. Both these writers try to compare the coastal features of Jave la Grande with modern Australia's, by realigning them. In 1994, McIntyre suggested that the writings of
Pedro Nunes supported his interpretation of the distortion that occurred on the Dieppe Maps.
Helen Wallis, Keeper of Maps at the
British Museum, referred in 1988 to the interpretation "explosion" on the subject of the Dieppe maps. She herself argued the case for discovery of Australia by "a local Portuguese voyage otherwise unknown" seventy years before the
Dutch, a chart of which was "presumably" brought back to Dieppe by the survivors of a
French voyage to
Sumatra led by
Jean Parmentier in 1529–30.
Cristóvão de Mendonça's role ''
Cristóvão de Mendonça is known from a small number of Portuguese sources, notably the famous Portuguese historian
João de Barros in
Décadas da Ásia (Decades of Asia), a history of the growth of the
Portuguese Empire in India and Asia, published between 1552 and 1615. Mendonça appears in Barros' account with instructions to search for the legendary
Isles of Gold. However, Mendonça and other Portuguese sailors are then described as assisting with the construction of a fort at Pedir (
Sumatra) and Barros does not mention the expedition again. McIntyre nominated Cristóvão de Mendonça as the commander of a voyage to Australia c. 1521–1524, one he argued had to be kept secret because of the 1494
Treaty of Tordesillas, which divided the undiscovered world into two-halves for
Portugal and
Spain. Barros and other Portuguese sources do not mention a discovery of land that could be Australia, but McIntyre conjectured this was because original documents were lost in the
1755 Lisbon earthquake, or the official policy of silence. Most proponents of the theory of Portuguese discovery of Australia have supported McIntyre's hypothesis that it was Mendonça who sailed down the eastern Australian coast and provided charts which found their way onto the Dieppe maps, to be included as "Jave la Grande" in the 1540, 1550s and 1560s. McIntyre claimed the maps indicated Mendonça went as far south as
Port Fairy,
Victoria; Fitzgerald claims they show he went as far as
Tasmania; Trickett states as far as
Spencer Gulf in
South Australia, and New Zealand's
North Island.
Claims of Portuguese words in Aboriginal Australian languages In the 1970s and 1980s, linguist
Carl Georg von Brandenstein, approaching the theory from another perspective, claimed that 60 words used by Aboriginal people of the Australian north-west had Portuguese origins. According to Peter Mühlhäusler of the
University of Adelaide: Von Brandenstein also claimed the Portuguese had established a "secret colony... and cut a road as far as the present day town of
Broome" and that "stone housing in the east
Kimberley could not have been made without outside influence". However, according to
Nicholas Thieberger, modern linguistic and archaeological research has not corroborated his arguments. Mühlhäusler agrees, stating that "von Brandenstein's evidence is quite unconvincing: his historical data is speculative – the colonisation being clandestine, there are no written records of it and his claims are not supported by the linguistic evidence he cites." In January 2014, a New York Gallery listed a sixteenth-century Portuguese manuscript for sale, one page of which contained
marginalia of an unidentified animal that the Gallery suggested might be a
kangaroo. Martin Woods of the
National Library of Australia commented: "The likeness of the animal to a kangaroo or wallaby is clear enough, but then it could be another animal in south-east Asia, like any number of deer species.... For now, unfortunately the appearance of a long-eared big-footed animal in a manuscript doesn't really add much." Peter Pridmore of La Trobe University has suggested the marginalia depicts an
aardvark.
Speculum Orbis Terrae '', an atlas published in 1593. Kenneth McIntyre argues the animal in the bottom right corner is a kangaroo. Other texts originating from the same era represent a land to the south of
New Guinea, with a variety of flora and fauna. Part of a map in
Cornelis de Jode's 1593 atlas
Speculum Orbis Terrae depicts New Guinea and a hypothetical land to the south inhabited by
dragons. Kenneth McIntyre suggested that although Cornelis de Jode was
Dutch, the title page of
Speculum Orbis Terrae may provide evidence of early Portuguese knowledge of Australia. The page depicts four animals: a horse, representing Europe, a
camel, to represent
Asia, a
lion, for
Africa, and another animal that resembles a
kangaroo, to represent a fourth continent. The latter creature features a
marsupial pouch containing two offspring, and the characteristically bent hind legs of a kangaroo or another member of the
macropod family. However, as macropods (including several species of
tree-kangaroo,
pademelon,
dorcopsis, and the
agile wallaby) are found in New Guinea and the
Aru Islands, this may have no relevance to a possible Portuguese discovery of Australia. Another explanation is that the animal is based on a
North American
opossum. McIntyre felt Cook's comment in his Journal, which at the 1982
Mahogany ship Symposium he cited as "this harbour will do excellently for our purposes, although it's not as large as I had been told", indicated he carried a copy of or had seen a copy of the Dauphin Map, and by implication was using it to chart his way along the eastern Australian coast. McIntyre acknowledged in his book that Cook may have been told this by the lookout or boat crew, but added it was a "peculiar remark to make." Reference to this remained in subsequent editions of
The Secret Discovery of Australia. In 1997,
Ray Parkin edited a definitive account of Cook's voyage of 1768–1771, transcribing the ''Endeavour's'' original log, Cook's Journal and accounts by other members of the crew. Parkin transcribed the relevant Journal entry as "...anchored in 4 fathom about a mile from the shore and then made a signal for the boats to come on board, after which I went myself and buoy'd the channel which I found very narrow and the harbour much smaller than I had been told but very convenient for our purpose." The log for 14 June also mentions the ship's boats sounding the way for the crippled
Endeavour. Nevertheless, the influence of McIntyre's interpretation can still be seen in contemporary Australian school curriculum materials.
Purported evidence from relics Mahogany Ship According to McIntyre, the remains of one of
Cristóvão de Mendonça's caravels was discovered in 1836 by a group of shipwrecked whalers while they were walking along the sand dunes to the nearest settlement,
Port Fairy. The men came across the wreck of a ship made of wood that appeared to be
mahogany. Between 1836 and 1880, 40 people recorded that they had seen an "ancient" or "Spanish" wreck. Whatever it was, the wreck has not been seen since 1880, despite extensive searches in recent times. McIntyre's accuracy in transcribing original documents to support his argument has been criticized by some recent writers. Murray Johns' 2005 survey of 19th-century accounts of the Mahogany Ship suggests that the eyewitness accounts actually relate to more than one shipwreck in the area. Johns concludes these wrecks were of early 19th-century Australian construction and are unrelated to Portuguese maritime activity.
The Geelong Keys In 1847, at Limeburners Point, near
Geelong,
Victoria,
Charles La Trobe, a keen amateur geologist, was examining shells and other marine deposits revealed by excavations associated with lime production in the area. A worker showed him a set of five keys he claimed to have found the day before. La Trobe concluded that the keys had been dropped onto what had been the beach around 100–150 years before. Kenneth McIntyre hypothesised they were dropped in 1522 by Mendonça or one of his sailors. Since the keys have been lost, however, their origin cannot be verified. A more likely explanation is that the "much decayed" keys were dropped by one of the limeburners shortly before being found, as the layer of dirt and shells they were found below was dated as around 2300–2800 years old, making La Trobe's dating implausible. According to geologist
Edmund Gill, and engineer and historian
Peter Alsop, the error by La Trobe is quite understandable, given that in 1847 most Europeans thought the world was only 6000 years old.
Cannon In 1916, two bronze cannon were found on a small island in Napier Broome Bay, on the
Kimberly coast of
Western Australia. Since the guns were erroneously thought to be
carronades, the small island was named
Carronade Island. Kenneth McIntyre believed the cannons gave weight to the theory of Portuguese discovery of Australia. However, scientists at the
Western Australian Museum in
Fremantle made a detailed analysis of the weapons, and determined that they are
swivel guns, and almost certainly of late 18th-century
Makassan, rather than European, origin. The claim that one of the guns displays a Portuguese "coat of arms" is incorrect. In January 2012, a swivel gun found two years before at
Dundee Beach near Darwin was widely reported by web news sources and the Australian press to be of Portuguese origin. However, later analysis by the
Museum and Art Gallery of the Northern Territory indicated it was also of
Southeast Asian origin. Further analysis suggests that the lead in the gun most closely resembles that from
Andalusia in Spain, although it may have been recycled in
Indonesia. The museum holds seven guns of Southeast Asian manufacture in its collection. Another swivel gun of Southeast Asian manufacture, found in Darwin in 1908, is held by the Museum of South Australia. In 2014, it was revealed that sand inside the Dundee beach gun was dated to 1750.
Bittangabee Bay as of Chinese construction. Kenneth McIntyre first suggested in 1977 that the stone ruins at
Bittangabee Bay, in
Beowa National Park near
Eden on the south coast of
New South Wales, were of Portuguese origin. The ruins are the foundations of a building, surrounded by stone rubble that McIntyre argued may have once formed a defensive wall. McIntyre also identified the date 15?4 carved into a stone. McIntyre hypothesized the crew of a Portuguese
caravel may have built a stone blockhouse and defensive wall while wintering on a voyage of discovery down Australia's east coast. Since McIntyre advanced his theory in 1977, significant research on the site has been conducted by Michael Pearson, former Historian for the
NSW Parks and Wildlife Service. Pearson identified the Bittangabee Bay ruins as having been built as a store house by the Imlay brothers, early European inhabitants, who had whaling and pastoral interests in the Eden area. The local
Protector of Aborigines,
George Augustus Robinson, wrote about the commencement of the building in July 1844. The building was left unfinished at the time of the death of two of the three brothers in 1846 and 1847. Other visitors and writers, including Lawrence Fitzgerald, have been unable to find the 15?4 date. Writing in
Beyond Capricorn in 2007, Peter Trickett suggests the date McIntyre saw may be random pick marks in the stonework. Trickett accepts Pearson's work, but hypothesizes that the Imlays may have started their building on top of a ruined Portuguese structure, thus explaining the surrounding rocks and partly dressed stones. Trickett also suggests the
Indigenous Australian name for the area may have Portuguese origins.
Kilwa Sultanate coins In 1944, nine coins were found on
Marchinbar Island by RAAF radar operator Maurie Isenberg. Four coins were identified as Dutch
duits dating from 1690 to the 1780s, while five with Arabic inscriptions were identified as being from the
Kilwa Sultanate of east
Africa. The coins are now held by the Powerhouse Museum, Sydney. In 2018 another coin, also thought to be from Kilwa, was found on a beach on
Elcho Island, another of the Wessel Islands, by archaeologist and member of the Past Masters group, Mike Hermes. Hermes speculated that this may indicate trade between indigenous Australians and Kilwa, or that they coins had arrived as a result of
Makassan contact with Australia. Ian S McIntosh's view is also that the coins were "probably introduced by sailors from Makassar... in the first wave of trepanging and exploration in the 1780s." ==Criticisms and alternative views of the Dieppe Maps==