In case of emergency, a last chance existed for the actual king in power to mobilize the population suddenly. Every noble, no matter his social class, had to participate in person with his weaponry and all of his personal guards made available. These were the estate armies. Whenever they were called upon, they were not allowed to fight for longer than 15 days, and their field of operations was restricted to within the borders of Hungary. The so-called "insurrectio" (noble "insurrection") was nothing more than an obsolete form of drafting, but it was valid until the Battle of Raab in 1809, mainly because it relieved the participating nobles of paying their taxes; but generally, these enlisted armada played a minor role in the Black Army, since Matthias decreased their participation gradually and called them up in large numbers early in his reign.