Petrus Thaborita

In the extended works by Thaborita van Bolsward is found information on the Frisian chieftains warlords Jancko Douwama and Haring Harinxma (the Donia ancestor).

Dutch writer Conrad Busken Huet used many of Thaborita's descriptions of historical figures in later books.

Petrus also dedicated a chapter in one of his books[specify] to Donia:About the death of Greate Pier, Pier Gerlofs Donia: "In dat selue iaer van 20 soe is ghestoruen groet Pyer, op Sinte Lucas nacht.

Of this Pier in Holland, in Brabant and other countries tales went around about his strength and his brutality and about his large eyes.

"[citation needed]Anton Reinhard Falck was the owner of the original documents, he lent these to the researchers Visser and Amersfoordt.