A veteran of a thousand battles, Terentius Melus served as Captain of the Third Company of the Neptunian Fists Chapter of the Adeptus Astartes. Having served for almost six hundred years, Melus has seen the best or worst of Humanity across countless worlds and battlefields. His experiences led him to fully embrace the concept of Astartes as Demi-Gods, scorning the lesser people of the Imperium as weak and unbecoming of the Human form. Despite this, he continued his valiant service as he believe that one day, Mankind could eventually evolve into beings comparable to Space Marines.
Terentius, born on the mining world of Sumia Secundus as Eadwig Leofric was the son of two miners. As soon as he could walk, he had to help in the mines, moving carts from where the miners were working to the surface. He was also used to crawl into the spots most workers could not reach to recover material, equipment, and bodies of deceased miners. From age five until he was ten, he worked in these harsh conditions until one day when his parents were killed in a mine collapse. After this, he fled the mines and wandered until he was captured by the local Arbites for abandoning his duties. He was set to be executed for this abandonment until he was confronted by a member of the Neptunian Fists chapter of the Adeptus Astartes. He was given a choice: Continue his ways and face his execution, or join the Emperor's Angels as an act of redemption. He chose the latter and was taken from his cell to the Neptunian Fists Fortress Monastery on Eskeon IX.