Kobus, ninth Count De Ruyter was a Redanian noble and commander who led the Tretogor forces in the Battle of Brenna. He was killed by a crossbow bolt, during a desperate charge against the Nilfgaardian "Venendal" division which prevented it from reorganizing in time to face the flanking attack of Blenheim Blenckert's forces. He was 56, at the time of his death. He is also credited with writing "Strategy", a historical treatise on military manoeuvres.