In 1482, a colossal clockwork gear fell through a inter-system rift, landing in the heart of the Great Expanse. This device of modron construction is a little more than 1900' in diameter and 300' thick at the center, tapering to 100' at its edges. A sentient energy resides in this alien device, one built long ago on the world Regulus. Modrons were sent to disable and dismantle the structure, but their attempts resulted in them becoming "rogue" modrons. The rulers of Regulus have since given up on their efforts to remove this alien device from Bal-Kriav.
When the device came to Bal-Kriav, it contained several stowaways. One of these was a rogue modron named Tetretz. This particular modron was one of many like it that helped build the device. Tetretz is an authority on clockworks, maugs, warforged, modrons, and automations.
Around 1485, the Gear Monument began producing living constructs like clockworks, maugs and warforged. These creatures have in turn created more of their kind and now roam the landscape of the Great Expanse. Some of the warforged collected into groups and then formed holdings of their own. The largest of these is Helmogorn. The warforged, maugs and other creations sometimes end up in the armies of distant empires. The halfling city-state Vorangrith has a number of mercenary companies which lease or sell Gurë legions to those with deep pockets.
In the 1600s, Engineen explorers came to the area in a very large blimp. They gathered dozens of small clockworks and took them back to Mechantus to be reverse engineered. Most of the things produced by the Gear Monument are neutral aligned. As a result, many join the Central Stability. Those that do not may take to settlements that welcome their kind.