[1] There he established the fortress of Passavant or Passava—a corruption of "passe avant", probably either a war-cry or the Nully family motto, however it is also found as a toponym in northeastern France—on the mountains between the Mani peninsula and the plain of Laconia.
[2][3] The castle became the seat of the Barony of Passavant, with four knight's fiefs.
It was militarily important, since it kept watch over the unruly Maniots and the Slavic inhabitants of Mount Taygetos, and Nully was named hereditary marshal of Achaea.
[1] John of Nully married a sister of Walter of Rosières, the Baron of Akova, and had a single daughter: Margaret of Passavant, the common heiress to both Passavant and Akova.
Margaret was sent to Constantinople as a hostage, however, and by the time she returned to the Peloponnese in ca.