King or Duke
What the exact title of the Frisian rulers was depends on the source. Frankish sources tend to call them dukes; other sources often call them kings.
Read more about this topic: Poppo (Frisian)
Famous quotes containing the words king and/or duke:
“He saved others; he cannot save himself. He is the King of Israel; let him come down from the cross now, and we will believe in him.”
—Bible: New Testament, Matthew 27:42.
“I don’t know what effect these men will have upon the enemy, but, by God, they terrify me.”
—Arthur Wellesley, 1st Duke Wellington (1769–1852)