The nobility and their families comprised only a small percentage of the population. The majority of the population however, was not always happy with this arrangement and frequently there were rebellions. These were most frequently brought on by tax increases. Unless quickly crushed, these rebellions could reach national proportions. Such rebellions were frequent throughout the period and several were large scale. Putting them down was expensive, as you had to quickly hire a lot of mercenaries and kill many of your tax paying subjects. Moreover, in the aftermath it was usually considered prudent to reduce taxes.