Winslau Da'k was a promising male Padawan serving the Jedi Order and the Galactic Republic as a Commander in the Grand Army of the Republic during the Clone Wars. When the Order was disbanded by the Sith-controlled Republic, Padawan Da'k was lost to the dark side of the Force after an encounter with Dark Lord of the Sith Darth Vader.
A Force-sensitive, Winslau Da'k was trained in the ways of the Force by the Jedi Order. Sometime around the Separatist Crisis he was selected by a Master as a Padawan who taught him all he knew. When the Clone Wars erupted between the Republic and the Confederacy of Independent Systems, Padawan Da'k took up the rank of Commander in the Grand Army of the Republic.
Surviving all three years of the war, this Master and Padawan pair managed to escape the execution of Contingency Order 66 by their troopers, an order which effectively disbanded the Jedi Order. Going to ground, Padawan Da'k encountered Dark Lord of the Sith Darth Vader, who corrupted him to the dark side unbeknownst to the man's master. Serving out their self-imposed exile on the remote planet Morcanth deep in the Unknown Regions, Da'k outsmarted his master and imprisoned him deep in the planet's frozen caves. While Da'k became a warlord on the world, his former master grew malnourished and ill deep in his prison.
When the Galactic Empire and the Sith were destroyed, the New Republic rose up to replace it. As word of the corruption on Morcanth reached the ears of the fledgling democracy and the newly reconstituted Jedi Order both groups sent agents to infiltrate the dictatorship. After students of the Order defeated Da'k in combat, the apprentices discovered his frail and dying master in the subterranean dungeons.