In the inhabited solar system nearest to their own, enthusiastic explorers from the Golarion System encountered the vesk, a reptilian race that lent credence to fears of extrasolar threats. Having already conquered the entirety of their own system, the warlike reptiles longed to expand, yet had mysteriously failed to receive Triune’s gift of interstellar travel. When the first explorers arrived via the Drift, the vesk received them warmly just long enough to decipher Drift technology—and then promptly began assembling Drift-capable war fleets aimed at their generous neighbors. In the wake of the disastrous Battle of Aledra, the independent planets of the Golarion System recognized the vast danger facing them and banded together for mutual defense, creating a single system-wide government capable of defending against the vesk. This coalition became known as the Pact Worlds.
For the next 250 years, the two systems would remain each other’s greatest threat, skirmishing over planets outside the direct authority of either autonomy, or else engaging in limited space battles along the cordons between their systems, too evenly matched for either to commit to a full-scale assault. This so-called Silent War finally came to an end in 291 ag, when a vast, world-devouring entity called the Swarm attacked both systems simultaneously. In danger of being completely overrun, the Veskarium—as the reptilians call their empire—and the Pact Worlds signed a formal alliance, together managing to force the Swarm out of their region of space. Yet while the alliance put an end to active hostilities and opened both systems up to trade with one another, citizens on both sides recognize that the alliance was one of convenience and could fall apart at any moment.
Fortunately for the Pact Worlds, not all extrasolar contact was so violent. The insectile shirrens arrived in 83 ag, bearing nothing but goodwill and quickly integrating into Pact Worlds society. Kasathas, who appeared in 240 ag on the massive worldship Idari, proved less willing to be assimilated wholesale, yet they quickly established themselves as valuable allies. Although other sentient creatures hailing from beyond the Golarion system occasionally arrive, brought back by Pact Worlds explorers or homing in on Absalom Station’s powerful Drift beacon, the already incredible diversity of life-forms in the system means that most such creatures can easily blend in and take up residence, provided they don’t stir up too much trouble.