There were three wars in Atlantia.
The first war in the history of the Atlantian continent occurred in the Fourth Age when six Turanian Kings sought to use the power of the Oracles for their own ends and fought against the four good kings. The Turanians were banished, along with their cohorts from Atlantia to the Nameless Lands to the North West and that part of the Nameless lands that became the home of the Shadow Kings was called Turania.
The second war occurred in the Fifth Age when the Turanian Kings sought to return to Atlantia and used the power of the Vulcan Oracle to caused the First Great Ice Age. The Four Kings united against them once more and fought a Battle of Souls between the Dragon's Horns two sheer cliffs either side of a deep valley famed for being a conduit to the Shadow Moon.
The good Kings were victorious through the work of the great Solar Manu but this caused the mountain ice to melt and rain and floods and earthquakes that lasted lifetimes. The valley became known as The Sea of Glass and the Shadow Kings were banished through a crevice to the pit of Helas or the Shadow Moon.
The third war occurred in the Seventh Age when the Mongolians enacted a ritual with the Vulcan secrets, which resurrected the Turanian Kings and caused the Second Great Ice Age. This was Battle of the Sea of Glass and the last battle in Atlantia for it caused the final destruction of the Islands.
In between these wars there were wars with the Mongolian raiders, who sought to retake the small but important Island of the Dead which held the empty Sepulchre of the last Godborn Manu and was said to bring power to whoever controlled it - for this reason it was shared equally by all the kingdoms except Mongolia and Turania.
There were also the Wars between the Godborn or Sons of Gods and the Mindborn, the Sons of men, those who followed the old Gods of memory and those who followed the New Gods of reason. This was essentially a war of North and South which found its apogee on the middle island of Toltecia. Visible fire was used for the first time on the heretics by the Toltecian Druida, who took advantage of the illness of their Manus to usurp their power.