The Highland charge was a battlefield shock tactic used by the clans of the Scottish Highlands which incorporated the use of firearms.
Prior to the 17th Century, Highlanders fought in tight formations, led by a heavily armed warrior elite that carried heavy battle axes or claymores (two-handed broadswords whose name comes from the Scottish Gaelic claidheamh mòr "great sword").
However, with the widespread use of muskets and cannon, such formations became vulnerable. As a result, in the 17th century, Highlander warriors developed a lighter, one-handed basket-hilted broadsword that protected the hand. This was generally used with a shield or targe strapped to the weak arm and a dirk or biotag "long knife" held in the other hand.
The Scottish and Irish warrior Alasdair Mac Colla is sometimes credited with inventing the Highland charge during the Wars of the Three Kingdoms to meet a particular set of battlefield challenges. The use of the charge greatly resembled older Celtic fighting styles of battle where one side would rush at the other in an attempt to break the line of battle.
The charge required a high degree of commitment as the men were rushing into musket range and would suffer casualties from at least one volley. Speed was essential to the charge, so the Highlanders preferred to employ the charge downhill and over firm ground; they removed clothing from their lower body for the same reason. They ran forward in clusters of a dozen (often blood relatives) which formed a larger wedge shaped formation. Once in effective musket range (60 yards) those with firearms would shoot; gun-smoke from this mass discharge having obscured enemies' aim, the Highlanders obtained further protection from the expected return volley from the opposing force by crouching low to the ground immediately after firing. Then, firearms were dropped and edged weapons drawn, whereupon the men made the final rush on the enemy line uttering Gaelic yells. On reaching striking distance the Highlander would attempt to take the opponent's sword or bayonet point on his targe while lunging in low to deliver an upward thrust to his enemy's torso.