Aldame was well-versed in battle history, and he clearly remembered that the longest recorded phalanx duel during the Sovereign War was the [Battle of Lucen], which lasted a full day, from the sun rising above the treetops until nightfall, when the Allied Army and the Imperial Army finally determined the victor.
Even excluding the parts involving troop deployment and front-line advancement, the actual time of engagement between the two sides lasted several hours.
