If we were slaves of our king and Emperor, subjected to him by your jurisdiction, it would not be permissible for us to separate ourselves from you [our duke]. Yet now, since we are free, and hold our king and Emperor the supreme defender of our liberty on earth, as soon as we desert him, we lose our liberty, which no good man, as it is said, loses save with his life. Since this is so, we are willing to obey whatever honorable and just requirement you make of us. If, however, you will something which is contrary to this, we shall return freely into that position whence we came under certain conditions to you.

-Anselm and Frederick, Counts of the Holy Roman Empire, Gesta Chuonradi II Imperatoris