The only major battle of the Elf Wars and the basic deciding factor.  Numbers not known, but basically the elves chased the aldar into the Tunnel World and kept them there for 18 days.  Fighting was mostly by longbows though the first day was melee.  After the 18 days, the elves moved enough magical power in to destroy the Tunnel World entrance and seal it.  The rest of the war involved hunting down those aldar still above ground.