Military action
This battle marks the true start of the rebellion, as it is the first true victory for the True Folk.
The Battle of the Irminsul was when Harla Chainbreaker, after spending years in the company of the still-free Blue Sky orc tribe, raised an army of multiple tribes, freed the surrounding countryside from enslavement, and marched upon the Irminsul with a combined host of thousands. Her antics were known by the elven and human lords of the Irminsul, but their arrogance forbade them from taking seriously what they still thought of as a simple slave rebellion. They were wrong. Harla's forces smashed the occupying False Folk after a weeks-long siege, eventually taking the city. The Irminsul became the rallying point for northerners everywhere; the Irminsul was visible for hundreds of kilometres away, due to its size, and if you could see it then you were free. The Irminsul was, and still is, the core of northlands territory.