The first few wars between the crews ended in a stalemate, and parts of The Asylum to split due to disagreements over pvp and war policy. The eventual Horsia War occured when they declared war against the remains of The Asylum, and their allies.
Horsia formed from a player SaltPigeon recruiting a large number of pvpers from other servers and bringing them to PirateCraft with the main intention of the crew to drive off the old and powerfull players from PirareCraft. However as the war continued, The Coalition and The Asylum found new allies (ArcherSquid and Adzy_) who along with TheSmilingFlea (Nationalistic) and other CLTN and TAS pvpers managed to win a large amount of the fights even though they where greatly outnumbered (some fights being as uneven as 12 Horsia members vs 3 from the TAS side)
In the final few weeks of active fighting, Horsia resorted to guerrilla warfare - using hit and run tactics which they largely still use.
The war ended after a couple months of fighting by Horsia leaving PirateCraft.