Why did Johan van Oldenbarnevelt argue that only Holland had the right to put him on trial?

Johan van Oldenbarnevelt argued that he should be tried exclusively by the judiciary of the province of Holland because he had acted solely as a civil servant of that sovereign province.12

In his view, his legal responsibility was limited to the authority of the province he served. This position reflected the broader constitutional tension of the era regarding the balance of power between the individual provinces and the federal union. Because no federal judiciary existed at the time, his political opponents bypassed provincial jurisdiction by establishing an extraordinary, ad hoc tribunal to try him for alleged crimes against the union.21