Bagenol is the prince paired with King Baligon in John Dee's De Heptarchia Mystica, one of the seven king and prince pairs recorded from the angelic sessions Dee held with the scryer Edward Kelley across 1582 and 1583 and preserved today as Sloane MS 3191. Bagenol shares Baligon's assignment to Friday and, by the system's day and planet correspondence, to Venus.
In the Heptarchia's structure, each day's prince serves under its king rather than ruling independently: the pairing is not a partnership of equals but a fixed subordination recorded consistently across all seven days. This is a separate stratum of Dee's angelic material from the forty eight Calls that Casaubon printed in 1659 or the ninety one Governors of the thirty Aethyrs that most twentieth century Enochian practice draws on. Those later systems organize the angelic hierarchy by elemental Watchtower and aethyric grade; the Heptarchia organizes it by the week and its planetary rulers instead.
Because the Heptarchia was never printed in Dee's lifetime, Bagenol survived only in manuscript until Joseph H. Peterson's modern edition and transcription of Sloane MS 3191 made the text broadly available, which is part of why the princes of the Heptarchia remain far less familiar today than the angelic ranks named in the later, published Calls.
Sources De Heptarchia Mystica (Sloane MS 3191), Joseph H. Peterson's editionJohn Dee, edited by Joseph H. Peterson with Arguing with Angels: Enochian Magic and Modern OccultureEgil Asprem