Definition of "castellan"

The inferior secular senators are ninety-two, containing the ten crown-officers, and eighty-two castellans. The latter are again divided into thirty-three great castellans, and forty-nine little castellans.

1851, Luther Calvin Saxton, Fall of Poland, volume 2, Charles Scribner, page 442

Castellans, often exercising control over a few villages and half a dozen small lordships, transformed their banal lordships into quasi-sovereign mini-states, independent of royal or comital sanction or control.

2003, Benno Teschke, The Myth of 1648: Class, Geopolitics, and the Making of Modern International Relations, Verso, page 86

The wave of attacks on the castellans in 1511 followed faction-fighting in Udine, in which castellans and their families were massacred by supporters of the Savorgnan.

2015, Christine Shaw, Barons and Castellans: The Military Nobility of Renaissance Italy, Koninklijke Brill, page 47