Biscia was born on 15 June 1575 in Rome, the second son of Bernardino Biscia and Vittoria Scapucci. Biscia's father was a minor noble and a consistorial lawyer. Biscia followed his father and received legal education before becoming a consistorial lawyer himself at the age of 20.[1]
Biscia was known as a great collector of books and manuscripts. In 1622, he employed theologian Leo Allatius to curate his personal library, considered to have been one of the most extensive of its day. Allatius later became Vatican librarian.[2] He was also a patron of mathematician and scientist Benedetto Castelli.[3]