Wikipedia
A grietman (literally: he who greets) is partly a forerunner of the current rural mayor in the province of Friesland, and partly the forerunner of a judge. The area of jurisdiction was the municipality or gemeente. In the judge function, the concept was also found in the Western side of the province of Groningen.
The grietman and judges were responsible for the administration and justice in the Frisian grietenij. The grietmannen were in turn elected or appointed, with the cooperation of the stadholder and the Executive Council. The eleven Frisian cities have mayors.
In the past it was thought that the heraldic Friese eagle was the privilege of a grietman and his descendants.
The Municipalities of Thorbecke law (promulgated in 1851) designated the Frisian grietman as mayors.