The Pilgrims initially called themselves the Resistance; they were a group of academics, philosophers, and engineers from the United Empire who had fundamental issues with the weight of government in daily life and the intrusiveness of corporate security. Unauthorized explorers, feisty academics, and craftsmen notorious for violating EULA's and warranties, this group eventually banded together, took over a colonization expedition, and broke off to form their own society.
Fate let them to a Kuiper Belt-like region that was rich in Endless artifacts and already under observation by the Sophons. From these new friends they took many hints in ship design and learned a great deal about survival in deep space. It was also among the ruins on these asteroids and ices that they became steeped in Endless lore and developed an almost mystical connection to the Endless civilization. There seemed to be a place where Dust goes beyond mere technology, and the mysteries of the universe are more than scientific puzzles...
Though retaining their fascination with philosophy and tinkering, their curiosity about origins, meaning, and actions changed them over a period of decades. They have become a a mystical, quasi-religious group that now calls themselves the Pilgrims.
Using a mix of Sophon and Empire technology, they travel the galaxy hunting the long-lost homeworld of the Endless in the hopes of finding answers to the most fundamental questions.