From the Medieval Ages to today, still effective. Found Caltrops

Life under Siege at Goodrich Castle

The Caltrop: A Weapon That's Barely Changed Over 2,300 Years

Caltrop - Wikipedia

The Caltrop: A Weapon That's Barely Changed Over 2,300 Years

13th-15th century AD. A group of nine large hand-forged iron caltrops with keeled spikes. 262 grams total, 89-93mm (3 1/2). From the family

Medieval Anti-Cavalry Caltrop Group

Forged iron, of two tapered bars forge welded at their junction with each terminal pointed. About 2 1/4 height, size as used on soft surfaces such as

MEDIEVAL CALTROP C.1200-1400

The Weirdest Medieval Weapons: A Journey into Historical Oddities

Mad Animals and (Medieval Times) Caltrops : r/RimWorld

Caltrop Weapons