Bayonet

Bayonets were weapon attachments that could be fit onto the muzzle of muskets and rifles, often as sharp spikes or knives.

During the American Revolutionary War, bayonets were utilized by soldiers from both the British and Continental armies, though generally as last-resort.

In most cases, bayonets were attached in preparation to receive a cavalry charge, as the crude spear they formed was effective at staking the riders or the horses, before they reached the otherwise vulnerable infantry. They were also utilized in close-quarters combat, when shooting would have been insufficient. However, some units (usually cavalry) would not have used fixed bayonets, as they would have carried swords which were more effective in close-quarters combat.

There were, in fact, several different types of bayonet; the ring bayonet, which was the most commonly used as it could be used with most firearms with a suitable sized barrel, the socket barrel, which was not as applicable to guns as soldiers would need a gun especially made to receive them, and so were not as commonly used as the ring bayonet, and the fixed bayonet, which was permanently fixed, but also very uncommon, as the weight of the knife would have offput the aiming of the soldier, and made it harder to store or carry.

The Assassin Connor Kenway was able to take rifles with bayonets from musket racks, or from disarming soldiers, in order to slash or impale nearby enemies. While a bayonet was embedded in a soldier's torso, Connor was able to fire the musket itself, and efficiently eliminate two opponents in quick succession.

Source

 * Assassin's Creed III - E3 Boston Gameplay Demo