From the website:
Jacques Grolet, born about 1663, was the son of Yvon Grolet and Marie Odon. He was baptized at the Church of St. Jean in La Rochelle, France. He and two friends, Jean L’Archeveque and Pierre Meusnier, had been members of the ill-fated La Salle Expedition of 1685-1687. Grolet and L’Archeveque spent several years in the Indian nations of Texas, and five years later surrendered to the Spaniards who found them there. Later reunited with Meusnier, the three men spent two years imprisoned in Cadiz, Spain, until their release in 1692. The conditions of their release required they become Spanish citizens and return to New Spain. As was custom in those days with non-Spaniards, his name was changed to Santiago Gurulé. On 10 December 1699, he married Elena Gallegos in Bernalillo, New Mexico.
This website includes a lot of interesting information about the Gurule family, including DNA results of family members. Click on this link to find out more.
Thanks to Angela Lewis for notifying me about this website.
P.S.: I personally am not descended from Santiago Gurule.