LUPUS, Joannes Baptistia. – A Florentine jurist who lived between the 16th and 17th centuries. He served as secretary to Francesco de’ Medici when the latter was sent by his father, Grand Duke Cosimo, to the court of Philip of Spain (1562–63).
Among his works are: *De illegitimis et de natalibus institutis liberis* (Venice 1611); *De usuris et commerciis illicitis* (ibid. 1611). A previous edition of the second work (ibid. 1577) is attributed to a certain L. Joannes Baptista Geminianus (a moralist born in S. Gimignano), giving rise to doubts as to whether these are two different authors.
BIBL.: A. Fontana, *Amphitheatrum legale seu Bibliotheca legalis amplissima*..., Parma 1888, cols. 593; G. Negri, *Istoria degli scrittori fiorentini*, Ferrara 1722, p. 249; G. Ermini, *Guida bibliografica per lo studio del diritto comune pontificio*, Bologna 1934, p. 37.