In 08 PN, a Army of Tigraen was shattered by Seleucis in a frontier skirmish. The survivors and their camp followers retreated back towards Tigraen - but all the high ranking officers and summoners had been killed. Left without leadership, the Orc tribes which made up the army began to follow their own leaders.
One band, led by Morroc, settled in the mountains southwest of Chibashu. The powerful, greenskinned Gurth took the rest of the warriors and the majority of the females southeast. His warriors spread out onto the plains they found there, and made war upon the hobgoblin horse nomads who claimed those lands. Many of Gurth's warriors were killed by the horsebows of the nomads, but Gurth's warriors swore mighty oaths to Gathal, and hunted them all down, killing the men and stealing the women and horses. The Orcs of Gurth smear themselves with red clay and black ash, and their full warhost is a truly ferocious sight.
The Gurtz Orcs are a horde, their numbers growing rapidly. No Orc has ruled Gurtz for more than two years, as their constant warfare sacrifices many to the god of Chaos. The rulership of the nation is influenced by a handful of elderly priests who back their own candidates to rule - and often see that rival rulers are destroyed.
For all the chaos at the top, Gurtz is an aggressive and expansionist place. The local orcs are outward looking, swiftly adopting new tactics and methods of warfare. Orcs still stream south from Tigraen into Gurtz, joining the growing hordes there.
The pressure to expand has grown so much that the Orcs have taken to the sea - at first in simple dugouts, then in sail or oar powered vessels of increasing complexity. Though not deep-sea sailors, Gurtz orcs are quite comfortable with coastal sailing.