What is a “portcullis”?

The story behind the answer

Because it slid vertically in grooves, this latticed barrier of iron or heavy timber could be raised by chains and a windlass and then dropped in an instant to block a gateway. Unlike a hinged door or a drawbridge, it formed a rigid grille that resisted rams and allowed defenders to stab or shoot through the gaps.

Portcullises were central to layered gatehouse defenses: attackers could be trapped between an outer door and the lowered grille while arrows, boiling liquids, or stones rained down from arrow slits and murder holes. The term comes from Old French (related to “sliding door”), and the portcullis later became a heraldic emblem—famously adopted by the Tudors and still used as a symbol of the UK Parliament.