He belonged to the illustrious family of Franche-Comté that faithfully served the House of Austria in high positions, specifically
Emperor Charles V and his son Philip II. He was the eldest son of
Nicolas Perrenot de Granvelle, who was Charles V's chief minister. Thomas was therefore the brother of Cardinal
Antoine Perrenot de Granvelle, Philip II's minister. Like the other members of his family, he was highly skilled in foreign affairs, which he demonstrated at a young age. He traveled to England in 1542 with the mission of persuading King
Henry VIII to join the Emperor in the war against France. In 1547, by order of Charles V, he returned to England, this time to convey to the new monarch, King
Edward VI, his condolences on the death of his father. They also entrusted him with missions among the princes of the House of Austria, participating in the negotiations and proxy marriage of the
Infanta Maria, daughter of Emperor Charles V, to her cousin,
Archduke Maximilian, son of Ferdinand I. This allowed him to develop a close personal relationship with the Archduke, the future Emperor Maximilian II. Other diplomatic missions on behalf of Charles V took him to visit the emperor's niece, Princess
Christina of Lorraine, in 1552. In 1564 Queen
Catherine de' Medici's pleas for his release finally persuaded Philip II to recall him from France. The King, who was very pleased with Chantonnay's loyalty and service, decided to send him as his ambassador to the imperial court of his Habsburg relatives in Vienna. ==Marriage and children==