Serkash Lahn was the Lord of Fire in the order of the Fire Force for almost a hundred years after the Galactic Empire arose.
He Started out as apprentice to Mialdir Cas in the final four decades of the Old Republic. He served the Conferacy of Independent Systems per Dark Lord Darth Sidious's request for a Fire Force member to serve under his apprentice Darth Tyranus for the Clone Wars.
At the end of the war Lahn was named Cas's successor to the title of Lord of Fire. That night Lahn killed Cas while he slept.
Durring Lord Sidious's reign as emperor Lahn had few duties. One was to find and direct Sidious's most recent apprentice Darth Vader to where Force sensitive children were. One such was Kale Zin the son of Lahn's former enemy Pock Zin. Vader refused to take the boy because he had almost been killed by Pock some years before.
After the Battle of Endor Lahn realized there were no more Sith to give him orders. Lahn was glad to be rid of the Sith. His happiness was short lived when the Sith Lady Lumiya came to him and asked where Lord Vader's other apprentice was.
When Lahn found out about the One Sith he swore to serve Darth Krayt and his servants. The Fire Force was now considered as part of the Sith Order as it had been at the very beginning. The One Sith would now contain more similarities to the former Sith Empires.
Serkash was later killed by his son, Kerlic Lahn. Kerlic was given an honorary title as Lord of Fire.
Lahn, again appeared as a member of the Sith Inquisition as Darth Cordas' apprentice. It is believed that he had been placed in stasis by one of his followers upon his death.