Hand-to-hand combat (sometimes abbreviated as HTH or H2H) is a physical confrontation between two or more persons at short range (grappling distance or within the physical reach of a handheld weapon) that does not involve the use of weapons. The phrase "hand-to-hand" sometimes include use of melee weapons such as knives, swords, clubs, spears, axes, or improvised weapons such as entrenching tools. While the term "hand-to-hand combat" originally referred principally to engagements by combatants on the battlefield, it can also refer to any personal physical engagement by two or more people, including law enforcement officers, civilians, and criminals. Combat within close quarters, to a range just beyond grappling distance, is commonly termed close combat or close-quarters combat. It may include lethal and non-lethal weapons and methods depending upon the restrictions imposed by civilian law, military rules of engagement, or ethical codes. Close combat using firearms or other distance weapons by military combatants at the tactical level is referred to in contemporary parlance as close-quarters battle. The United States Army uses the term combatives to describe various military fighting systems used in hand-to-hand combat training, systems which may incorporate eclectic techniques from several different martial arts and combat sports. History Hand-to-hand combat is the most ancient form of fighting known. A majority of cultures have their own particular histories related to close combat, and their own methods of practice. The pankration, which was practiced in Ancient Greece and Rome, is an example of a form which involved nearly all strikes and holds, with biting and gouging being the only exceptions (although allowed in Sparta). Many modern varieties of martial arts and combat sports, such as some boxing styles, wrestling and MMA, were also practiced historically. For example, Celtic wrestling is mentioned in the Tailteann Games dating back from somewhere between 1839 BC to 632 BC (academics disagree) to the 12th century AD when the Normans invaded. Other historical forms of close combat include the gladiator spectacles of ancient Rome and medieval tournament events such as jousting. Military organizations have always taught some sort of unarmed combat for conditioning and as a supplement to armed combat. Soldiers in China were trained in unarmed combat as early as the Zhou dynasty (1022 BCE to 256 BCE). Despite major technological changes such as the use of gunpowder, the machine gun in the Russo-Japanese War and the trench warfare of World War I, hand-to-hand fighting