Juw Juwinga (alias Jongema) of Bolsward was a Frisian chieftain that earned great fame in the struggle against the (Dutch) ‘infidels’. When Albrecht of Bavaria, count of Holland, threatened Friesland in 1396, Juw was chosen as potestate of Friesland. He advised luring the enemy into the land. The Schieringers limited their defense to the coastline. The Dutch were defeated at Schoterzijl (in Weststellingwerf) where Juw was slain on August 29, 1396. Juw was also known as Julius Jongema, and Petrus Thaborita wrote his name as Ju Jonghema.