Wikipedia
Nihang
The Nihang are an armed Sikh order. They are also referred to as Akali (lit. "the immortals"). Nihang are believed to have originated either from Fateh Singh and the attire he wore or from the "Akal Sena"(lit. The Army of the Immortal) started by Guru Hargobind. Early Sikh military history was dominated by the Nihang, known for their victories where they were heavily outnumbered. Traditionally known for their bravery and ruthlessness in the battlefield, the Nihang once formed the irregular guerrilla squads of the armed forces of the Sikh Empire, the Sikh Khalsa Army.