Sea of Fallen Stars

The Sea of Fallen Stars, also known as the Inner Sea, was the largest inland body of water in Faerûn. Its major areas included the Dragonmere (Lake of Dragons) on the west, the Dragon and Easting Reaches on the north, the Alamber Sea on the east and the Vilhon Reach on the south. The sea floor was covered with hundreds of shipwrecks.

History
The name of the sea was from the origin story which stated that the Inner Sea formed when the four Inner Seas merged together, coinciding with the loss of entire continents from earthquakes, fires, and windstorms due to a star sent by deities to punish the titans' arrogance. Other theories maintained it was actually the eggs of the first dragons raining down onto the planet.

Tens of thousands of dragon eggs did hatch soon after the event, though the real reason for the destruction was the primordial Asgoroth the World Shaper hurling an ice moon down to Abeir-Toril's surface.

Sarrukh accounts dated around -31000 DR mentioned a "changing of the stars" in relation to this event. Few knew what this really signified, but the fact was Ao created a clone of Abeir-Toril and sent the new world to another realm, with different stellar cartography.

Regardless, this event, known as the Tearfall caused a climate shift that wiped out the batrachi civilization.

Inhabitants
Home to many types of aquatic life, the sea could be quite dangerous. The sea was home to kingdoms of aquatic elves, merfolk and sahuagin. With the exception of a notable violent excursion in 1369 DR, these races rarely interacted with the coastal land folk.

Islands
There were numerous islands in the Sea of Fallen Stars. The Pirate Isles were a group of about sixty rocky islands notable for the concentration of pirate activity that occurred there. Prespur, sometimes known as the Isle of Prespur or the Isles of Prespur, consisted of a main island under Sembian control and a smaller unoccupied island called Traitor's Isle. Alaor was a former Thayan shipyard turned autonomous. The Ship of the Gods was an island volcano in the Alamber Sea. The Whamite Isles were a small chain of islands once ruled by a great Khan.

Coastal
The Sea of Fallen Stars had coastlines in many different lands, including Aglarond, Altumbel, Cormyr, Chessenta, Chondath, the Dalelands, Impiltur, Sembia, Mulhorand, Priador, Thay, Thesk, Turmish and Unther.

Territorial waters
There was a recognized territorial limit of ten miles (16.1km) offshore among all the nations on the Sea of Fallen Stars. Areas of sea further than ten miles from the nearest land were considered neutral territory. Any attacks on shipping within a country's waters were considered to be acts of war. For most areas these boundaries were clear, but they became more ambiguous in Mulhorand, Thay, and Unther due to continual border disputes.