Velen

Velen also known as the No Man's Land, was a province of Temeria with capital Gors Velen latter Crow Perch conquered by Nilfgaard during the Third Northern War. Even before the war, Velen was never a prosperous place. What little wealth the peasants had was the result of backbreaking toil tilling fields, fishing the dangerous rivers and swamps, or braving the woods in search of game and herbs. What industry there was mostly revolved around boat building, and the tanning of hides. There are also a handful of quarries and mines in the northern reaches of No Mans Land, nearer the border with Redania. 

The Witcher 3: Wild Hunt
Velen or No Man's Land is one of three (four with Blood & Wine expansion) major locations within Southern Redania (Oxenfurt,Novigrad),Skellige Islands and Toussaint.

The majority of Velen is swampland, low lying, and unwelcoming (if not outright deadly) to any who are unaccustomed to it. The waterways, rivers, and bogs are home to drowners and waterhags, while the forests and hills to the north and east and swarming with ghouls, fiends, wraiths and far worse in the best of times. In the bleak days following the conquest by Nilfgaard, Velen has sunk even deeper into poverty and despair. Bandits prowl the roads, flesh-eaters haunt lonesome shacks, and Nilfgaardian cavalry tramples the fields....

Rulers

 * Vserad - Baron of Crow's Perch and Lord of Velen
 * Phillip Strenger - or so called Bloody Baron, Baron of Crow's Perch and Lord of Velen (self-styled)