Pierre Segur born in 1429 in Dijon, the capital of the Duchy of Burgundy. He became a soldier and strategist in the Burgundian army. Around 1476/77 Segur participated in the siege of the capital of Lorraine, Nancy. After several hard winter months, the siege came to an end, as on January 5, the Duke René II of Lorraine and his army attacked the Burgundians. Segur fell in battle as he tried to protect his Duke, Charles the Bold.
Segur revived as an Immortal, and he left the military to begin a quieter life. He made a fortune as a merchant several times over the years, trading in gold, spices, and fine silk from the Orient. Segur married twice. Once the widow of a business partner, who after the death of her husband was left destitute. His second wife, Margaretta, was married for love, and he stayed with her until she died in 1658, aged 86.
From his days as a soldier, Segur was a skilled swordsman. He also exercised regularly, but he called out no other immortals. If someone challenged him, however, he responded honorably.
In 1700, Segur was living as a wealthy merchant in Paris. There he was visited by his friend Duncan MacLeod, who was there to attend the burial of a mortal friend, Alain Jaubert, whose birth MacLeod had seen, now dead of old age. The loss took MacLeod hard. Segur told him, "We are Immortal, and their loss is the price we pay." He thought the price worth it for their gain in knowledge and wisdom.
Outside the church they were confronted by Martin Hyde, who challenged Segur. Duncan wanted to fight in Segur's place, but Segur held him back. He gave Duncan a bottle of old cognac and told him to meet him on the steps by the bridge in one hour, and they would drink it together. But Segur did not come to the meeting place, Hyde having bested him. MacLeod would one day share the cognac at the bridge with another friend; Richie Ryan.