When Henry of Navarre came to the throne of France, he wished Montaigne, whom he had again visited in 1587, to come to court, but the essayist refused.
His work, which appeared in three parts, entitled respectively History of the Rise of the Huguenots of France (2 vols., 1879), The Huguenots and Henry of Navarre (2 vols., 1886), and The Huguenots and the Revocation of the Edict of Nantes (2 vols., 1895), is characterized by painstaking thoroughness, by a judicial temper, and by scholarship of a high order.
In 1590 he sent an expedition to Provence in the interests of the Catholic League, and followed it himself later, but the peace of 1593, by which Henry of Navarre was recognized as king of France, put an end to his ambitions.
Again a widow in 1579, she had some influence at the court of Henry III., and negotiated his reconciliation with Henry of Navarre (1588).
On the 10th of June 1584 the death of Monsieur, the duke of Anjou, brother of King Henry III., made Henry of Navarre heir presumptive to the throne of France.
The reformers had now no leaders, and their situation seemed as perilous as that of their co-religionists in the Netherlands; while the sieges of La Rochelle and Leiden, the enforced exile of the prince of Orange, and the conversion under pain of death of Henry of Navarre and the prince of Cond, made the common danger more obvious.
Next year he followed the example of Henry of Navarre by abjuring the Protestant faith.
After the accession of Henry of Navarre to the throne of France, Vieta filled in 1589 the position of councillor of the parlement at Tours.
By his wife Louise of Lorraine, daughter of the count of Vaudemont, he had no children, and on his deathbed he recognized Henry of Navarre as his successor.