Eustace was appointed one of the papal commissioners to investigate and settle the attempt by Savaric FitzGeldewin the Bishop of Wells to take over Glastonbury Abbey as Savaric's new cathedral site. The commissioners set forth a plan, but Savaric died soon after and Pope Innocent III was persuaded to disallow the move. During King John's dispute with the pope over the election of Stephen Langton as Archbishop of Canterbury, the pope once more chose Eustace as a commissioner in August 1207, along with William of Sainte-Mère-Eglise, the Bishop of London, and Mauger the Bishop of Worcester. The commission tried to convince the king to accept Langton, but eventually in March 1208, they pronounced an interdict on England because of John's refusal to accept Langton. In July 1208 the commissioners once more attempted to negotiate with John, this time in company with Langton's brother Simon Langton. They waited eight weeks for a meeting, but the king never received them. A year later, the king finally met with them at Dover. Although an agreement was reached, it was never put into effect, and negotiations reached a stalemate. In November, the commissioners declared John excommunicated. Eustace had been in exile since the proclamation of the interdict in 1208. In 1212, Eustace journeyed to Rome to complain to Innocent about John's oppression of the English Church.