Infantry square

An infantry square, also known as a hollow square or square formation, was a musket-era historic close order formation used in combat by infantry units, usually when threatened with cavalry attack. To deploy its weapons effectively, a traditional infantry unit would generally form a line; but the line was vulnerable to more nimble cavalry, which could sweep around the end of the line, or burst through it, and then attack the undefended rear or simply sweep along the line attacking the individual footsoldiers successively. By arranging the unit so that there was no undefended rear or flank, an infantry commander could organise an effective defense against cavalry attack. With both the development of modern repeating firearms and the demise of cavalry in warfare, the square formation is considered obsolete and is effectively never used in modern day warfare.