What is “a merlon”?

The story behind the answer

In a crenellated parapet, defenders sheltered behind the protective uprights between the gaps (crenels), then stepped out to shoot or throw missiles before ducking back into cover. These sturdy blocks were crucial for withstanding incoming arrows and bolts while enabling controlled, intermittent fire from the wall walk.

Together with the gaps, they form “crenellations,” the classic tooth-like silhouette of medieval castles. Their shapes varied by region and period: in Italy, Ghibelline “swallow-tailed” designs contrasted with the square Guelph style. As warfare evolved, some were pierced with arrow loops or gunports to accommodate crossbows and early firearms. In England, adding such fortifications often required a royal “license to crenellate,” signaling both defense and status.