Jeffers was a Rogue Trader Militant during the Great Crusade whose Warrant of Trade was signed by the Emperor himself. He commanded one of the first fleets to leave the Sol System at the outset of the Crusade and later rediscovered the Knight World Chrysis. He quickly realized its Knight Houses could be valuable allies for the Emperor's armies and in his reports, Jeffers pointed out the Knights' many virtues and emphasized Chrysis' value to the Imperium as a source of born and bred warriors. The Administratum agreed with Jeffers’ findings and set about finding the rest of the long-lost Knight Worlds.
- 1: White Dwarf September 2018, pg. 37 — Designers' Notes: Pushing the Boundaries
- 2: Codex: Imperial Knights (6th Edition) — The Imperial Knights - The Coming of the Imperium