The Ur (as the Precursors are called) are an ancient civilization shrouded in mystery. Though little is known about them, their presence is felt throughout the Hegemony and modern society is built on the discoveries from this lost culture. Archaeologists are unsure what they looked like because some Ur sites are built for beings the size of giants, while others are built for those only a few feet in size. Their language has millions of unique sigils, the meanings of which are hotly debated. There are conflicting theories as to why the Ur disappeared, but the bones of their civilization fuel studies and advancements throughout the Hegemony.