Cited by Bejarano Pellicer who establishes that he Juan Márquez had maintained a workshop in Seville since 1570 but it appears likely that he was imprisoned in 1570 for financial debt. He was aided by the merchant Andrés Venegas, guarantor in the lease of his house to whom he owed 12 ducats, and who sold a harp that Juan Márquez had given him for which he obtained 30 reales (1020 mrs) with which he paid a month's rent on behalf of the violero ( bejarano2013-1, 525).
Gómez Fernández (gomezfer2017, 267) reports him described as a “Maestro de hacer vihuelas” in 1594, in connection with the dukes of Medina-Sidonia. In 1594, Juan Márquez sold a guitar to the oldest son of the dukes, Guzmán, XI count of Niebla.
It is possible that he is related to the violero Bartolomé Márquez and, active in the first decade of the seventeenth century. Pending further research, he is listed here as a possible son.