Sepoy (/ˈsiːpɔɪ/), related to sipahi, is a term denoting professional Indian infantryman, traditionally armed with a musket, in the armies of the Mughal Empire and the Maratha.

[1][2] The term "sipahi" (or sometimes "sepoy") continues in use in the modern Indian, Pakistan and Nepalese armies, where it denotes the rank of private.

The term sepoy is the anglicised form of the Persian word sepāhī (سپاهی), meaning the traditional "infantry soldier" in the Mughal Empire.

[3] The term sepoy came into common use in the forces of the British East India Company in the eighteenth century, where it was one of a number of names, such as peons, gentoos, mestees and topasses, used for various categories of native soldier.

[4] The earliest sepoys used matchlock muskets and operated bulky and inefficient cannons to a limited extent during the reigns of Babur Akbar when archery and fighting from horseback was more common.

By the time of Aurangzeb the Mughal armies had advanced significantly and utilized a wider range of weapons to win battles.

[6] By the 18th century individual Nawabs employed their own sepoy units as did the European merchant companies established in parts of India.

[7] In the Bengal Army however, recruitment was only amongst high caste Brahmin and Rajput communities, mainly from the present day Uttar Pradesh and Bihar regions.

[3] This combination of factors led to the development of a sense of shared honour and ethos amongst the well drilled and disciplined Indian soldiery who formed the key to the success of European feats of arms in India and abroad.

Our warlike neighbours were the first to introduce into India the system of drilling native troops and converting them into a regularly disciplined force.

Cipaios from Angola provided part of the garrison of Goa during the final years of Portuguese rule of that Indian territory.