The buckler is a small shield that became very popular in the 16th century. The name is derived from the Old French word bocler, meaning having a boss, a raised centre, which was a feature of the small shield. The word swashbuckler is derived from swash, which means the sound of a heavy blow, combined with buckler. It first referred to the swordsmen banging his sword against his shield and then came to mean the bravado of those that did.

The buckler was an important weapon for light infantry. Rather than being attached to the forearm like larger shields it was held in the non-sword hand and used to deflect blows from the opponent. It was an effective close contact weapon.

Machiavelli described (in 1521 in the Arte of Warre) how at the battle of Barletta in 1503 the Spanish sword and buckler men dealt with the Swiss pikemen:

the Swiss pressed so hard on their enemy with their pikes, that they soon opened their ranks; but the Spaniards, under the cover of their bucklers, nimbly rushed in upon them with their swords, and laid about them so furiously, that they made a very great slaughter of the Swiss, and gained a complete victory.

The unarmoured English bowmen at the Battle of Agincourt in 1415 had bucklers as part of their defence. Richard III’s troops during the later part of the War of the Roses (1455-1485) were recorded as carrying swords accompanied by iron bucklers.

The boss at the centre of the buckler was sometimes replaced with a point, which allowed the buckler to be used more offensively. This modification may have contributed to its demise in England. Elizabeth I passed a statute in 1562 prohibiting any buckler with a sharp point being allowed in London. The sword and buckler also went out of fashion for sparring and the rapier and dagger becoming the more gentlemanly weapons.

For an excellent history of the buckler I recommend the ARMA website page.