Whilst Chinese and Javan explorers and traders had mapped out its western fringes by c. 800 (though apparently completely missed Australia) it would not be until the travels of Marco Polo that the ocean's existence came to European attention. On the Leifian side it waited until Hjortur Elvarsson reached it overland in 1281. Elvasson described it as calm - 'roa', giving it its name. A sea route around the southern tip of Tawantinland was only confirmed by the voyages of Bjarni Okwesson in 1461.
Chinese explorers made the first crossing of it in 1420 via Hawaii and were soon sending yearly trading expeditions to Mexica and Tawantinsuyu. In turn both Mexica and Tawantinsuyu came to appreciate the ocean and, building their own fleets largely modelled on Chinese Junks, made their own expeditions to cross it. Mexica looked to supplant and dominate the trade between Leifia and Asia while the Tawantin sought a more peaceful trade, discovering and penetrating into the Polynesian islands long before Europe. Violence, on both sides, followed. Mexic fleets fought Chinese and Japanese forces for the right to carry the bulk of Leifian trade and later, for the Hawaiian Islands. In the south the spread of gunpowder weapons by the Tawantin caused havoc in the Tongan and Maori islands and on Papua.
Once the European powers had divided up the Australian landmass they turned their attention to the islands of the south Roasjoinn. Various island groups are now under European juristiction whilst the larger groupings maintained their independence thanks to Tawantin insistence and a series of treaties.
Currently trade is largely funnelled to the south of Tawantinland through the Okwesson Straits. A passage to the north of Leifia although confirmed by the exploits of Karl Therkildsson Mathiasson is effectively unusable thanks to near-permanent sea-ice. However this may soon change as Tawantinsuyu is building a gigantic ship canal through the relatively thin isthmus connecting Leifia and Tawantinland. This will shorten sailing times dramatically between the oceans and provide a huge boost to the communtities of the eastern Roasjoinn.
The Roasjoinn's reach is sometimes disputed with regards to Asia as there is a long chain of islands dividing the Roasjoinn into smaller seas all along its western fringes. However the following states are usually said to be 'on' the Roasjoinn.
- Tondo (China)
- Kingdom of Singapore (United Netherlands)
- Various Papuan City-States
This continent includes much of the myriad of islands that lie in the southern Roasjoinn.
- Drehu Federation
- Loaisa Islands (France)
- South Azores (Portugal)
- Svealandic Polynesia (Svealand)
- Danish Polynesia (Denmark)
- Frysian Polynesia (Fryslân)
- United Maori States
- New Zeeland (United Netherlands)
- Military Japan (Japan)
- Lingít Aaní
- Klallam Federation
- Chinese Leifia (China)
Tawantinsuyu occupies the entire western seaboard of Tawantinland.
The polar continent of Antarctica is usually judged to form the southern border of the Roasjoinn (though sometimes its surrounding waters are separately named the Southern Ocean). Its lands are uninhabited but are disputed between the United Netherlands, the Kalmar Union and Tawantinsuyu and await a final treaty.