What role did Johan van Oldenbarnevelt play in negotiating the Union of Utrecht in 1579?

In 1578, as the threat of a total reconquest by Spanish armies under the Duke of Parma grew, Johan van Oldenbarnevelt served as one of the key negotiators of the Union of Utrecht, which was concluded in January 1579.1

During these negotiations, Oldenbarnevelt’s primary objective was to secure a politically dominant position for the province of Holland. He argued that Holland, having borne the brunt of the revolt alongside Zeeland for nearly seven years, was entitled to a position of strategic and political preeminence within the new union. His involvement in these proceedings also facilitated his closer contact with William the Silent. The resulting agreement served as a foundational, albeit makeshift, constitution for the United Provinces until 1795.1