Bordels magistrate born in 1553 and died in 1631.
His grandfather Bernard de Rosteguy, a wealthy wine-grower born in Juxue, had settled in Saint-Macaire (Gironde) in 1510. His father, by purchasing the post of notary-councillor and secretary of the household and crown of the King of France, became lord of Lancre, losing his original surname. Pierre attended the Jesuit college, received his doctorate in law in 1576 and completed his legal and theological studies in Italy (Turin) and Bohemia. On his return to the Gironde, thanks to his knowledge of Italian, he was appointed tutor to Pierre de Medici and in 1582 councillor to the parliament of Bordeaux. He returned to Italy, where he took part in the Jubilee of 1600 in Rome.
In May 1609, Henry IV sent him to Laburdi to investigate local witchcraft . By that time he had already published (Paris, 1607) A Tableau de l'inconstance et l'instabilit de toutes choses, or It is seen that in God alone there is true constancy that wise men do not see . At Laburdi he proceeded imbued with all kinds of Satanist interpretations, supported by his companion before President Espaignet and enjoying full powers over all local authorities. Over the course of four months, Lancre would burn at the stake nearly 60 people of all conditions. The fruit of his readings and this experience is the famous Tableau de l'inconstance des mauvais anges et d'mons o il est amplement trait des sorciers et de la sorcellerie (Paris, 1612), in which Rosteguy pontificates on the evil Laburdine inclinations, the intrinsic perversity of women, the preparation of the Sabbath, poisons, the crowing of the cock, the demonological pact, marks and feasts, dances, intercourse with the devil, lycanthropy, healing practices, apparitions, the act of faith of Logroño or 1610, witch-priests, the black mass, legal considerations, etc. The last chapter is significantly titled "Qu'il faut faire mourir les sorciers (bien qu'ils ne soient pr venus d'aucun mal fice) pour avoir t simplement au sabbat, pactis avec le diable, et fait audit lieu tout ce qu'ordinairement les autres sorciers accotum d'y faire."
Two years later he became an advisor to the king, continuing in his post at the Bordeaux parliament until 1616. In 1620 his house on the banks of the Garonne at Santa Cruz de Monte (Cadillac) was visited by the king and its gardens in particular became a place of pilgrimage, where Lancre remained until his death in 1631, after having published two more books: Le Livre des princes (Paris, 1617) and L'incr dulit et m'creance du sortil ge pleinement convaincue (Paris, 1622).
In 1982, the Aubier Montaigne publishing house in Paris reissued his capital work, providing it with a magnificent prologue by Nicole Jacques Chaquin. This has been able to interpret the ideological role of Lancre in this area of the Basque Country:
"As the king's representative in a troubled region, De Lancre emphasises the disorders caused by a love of liberty that is detrimental to the proper functioning of central power, and takes up again the great myth of witchcraft as a social scourge. Living in an age of numerous disagreements with Spain - the mission entrusted to Espagnet, which Lancre discusses at length at the beginning of the Tableau, bears witness to this - he will prove to be extremely sensitive to the unrest that these border disputes might create and to the contaminating effects of Spanish civilisation on the French Basque Country. Finally, coming from the Bordeaux citizen and commercial nobility, Lancre will evidence of a lack of understanding of the social and economic habits of the rural Laburdi, which will present to him with an effect of foreignness that he will "naturally" attribute to the diabolical."