All that is known is that the movement known as the technomancers suddenly left, and the new king wanted to know why his father had banished them.
They had started as a small movement a couple of people who discovered that they could destroy rocks in their fields by mixing sulfur, charcoal, and dried fertilizer and then burning it would cause the same effect as a mage with a detonation spell, and at a tenth the cost. After that they began looking for other methods of simulating the mages by using common materials, and it grew from there.
As the locals began recognizing the significance of these finds, so did the wizards who had controlled many aspects of society and commerce for many years. The old king did not know what to think of this new way of doing things, it seemed harmless but it was causing distress to the many wizards who acted as advisor and aid in many places.
While the king took no stand on the issue, his chief mage advisor convinced him to simply look the other way while the main camp of the technomancers was dealt with.