The flag of Friesland has seven diagonal (canton to lower fly) equal-length stripes alternating blue and white from left to right. Equally spaced along the centre white stripe are three red stylised spatterdock leaves. Equally spaced along each of the other two white stripes are two red stylised spatterdock leaves.
The seven red pompeblêden (leaves) are a reference to the Frisian "sea countries" in the Middle Ages; independent regions along the coast from Alkmaar to the Weser who were allianced against the Vikings. Though there were never exactly seven of these, the number seven was chosen to symbolise "many". The current Frisian flag is derived from medieval coats of arms of Frisian kings, whom in turn derive from older Scandinavian coats of arms.