Ailendamus is around three times as large as three of its southern neighbors: Kaliv, Calanfer and Gaiil-Drome, who are generally known as the Dawn Concordat. Ailendamus has a navy, but not a match for either Pheislant nor the one of Belchaus Meron.
28 years before the events of book 6, the war of Petril’s Folly had set Ailendamus and six other nations against the three kingdoms mentioned above. The war apparently ended without either side claiming a complete victory over the others.
Ailendamus is a generous sponsor of Wistram Academy which bought them lots of favorable coverage in spyglass-broadcasts. Viltach supports Ailendamus, by making Wistram's policy one of strict neutrality in the developing situation.
Ailendamus' navy was also blocking sea trade that was going towards the (landlocked) Dawn Concordat, defying Pheislant's rule and "vanishing" ships that were loading goods for either of the three nations that made up the Concordat. The Ullsinoi faction of Wistram was faking orders for Admiral Dakelos that they claimed were secret orders from Itorin himself, sailing on an Illusion of the Ailendamus' flagship which is the Itorin's Pride. That ruse led Dakelos into mock-attacking Belchaus Meron's navy, who took the threat seriously and easily overwhelmed Dakelos' ships and crew.