Orcs of the North

Warlords: Call to Arms
They are described in Warlords: Call to Arms as "Orcs of the North are a particularly strong breed of orcs. These chaotic green warriors crave the excitement of battle."

Their special unit is Battle Axeman.

They border the Mountain Trolls, Night Elves and the Men of the West.

Warlords 2: Rise of Demons
They are described in Warlords 2: Rise of Demons as "Intense training gives northern orcs  the ability to strike with great power."

Warlords: Epic Conflict
They are described in Warlords: Epic Conflict as "A group of orcs, who tolerate brutal living conditions to make themselves tougher. "

Lore
Note, the following is fanon (fan-canon) and is NOT to be considered absolute canon

The orcs of the north are one of the races that inhabit Beneril. Before the first war of Beneril, the orcs of the north and the orcs of the south co-existed as one, but when the war first started to arise and when the Orcs of the South needed all the support of the northern orcs, they abandoned them and took place in the northern mountains of Beneril. These orcs are stronger than any other breed of orcs and crave for battle every second they breathe. No other race has considered to make amends with them as they are very hostile and dislike any thought of peace. It is said that these orcs train against themselves and only those strong enough to endure a fight with as many wounds as possible without even flinching or falling to their knees are worthy to be in their army, and those who are weak are left to die or banished from the land. Their territory has a unique characteristic and it is the crimson red that washes the land, the skies and the sea. They are located at the north of Beneril and their territories are Goroth, Thareth and Chogoth, which is the capital of their land and it borders with Senshan (Men of the West), Battakka (the Mountain Trolls) and with Azzitha and Chan (the High Elves). They train intensively and craft axes that can chop an enemy's head easily, making them a force to not be reckoned with, as they can finish a whole army in a matter of seconds. Before and during the first war of Beneril, the northern orcs trained themselves in the arts of strength and brute force, thus leading them to have a special unit which is the Battle Axeman, who can chop an opponent's head in just a single strike. After this war, before and during the second war of Beneril, they decided to train not only strength but also strategy and endurance, which led them to create another special unit which they named the 'warrior monk', a warrior wielding a pole that is capable of knocking down many units before breaking a sweat. There is no known political ideology of these race, but many think the strongest orc is the ruling orc. Their banner of war consist of a plain red banner with some symbols painted in it.