The Gurunsi, or Grunshi, are a set of related ethnic groups inhabiting northern Ghana and south and central Burkina Faso. Oral traditions of the Gurunsi hold that they originated from the western Sudan passing through the Sahel. While it is unknown when the migration occurred, it is believed that the Gurunsi were present in their current location by 1100 AD. Following the 15th century, when the Mossi states were established to the north, Mossi horsemen often raided Gurunsi areas for slaves, but the Gurunsi peoples were never fully subjugated, remaining independent. According to doctor Salif Titamba Lankoande, in Noms de famille (Patronymes) au Burkina Faso, the name Gurunsi comes from the Djerma language of Niger words “Guru-si”, which means “iron does not penetrate”. It is said that during the Djerma invasions of Gurunsi lands in the late 19th century, a Djerma jihadist leader by the name of Baba Ato Zato (better known by the Hausa corruption of his name: Babatu) recruited a battalion of indigenous men for his army, who after having consumed traditional medicines, were said to be invulnerable to iron. They set up the Zabarima Emirate within Gurunsiland, which makes up far northern Ghana and southern Burkina Faso. The people who speak closely related Gur languages and dialects and classed by the Mossi under the umbrella term Gurunsi form an arc of village communities mostly organised as defensive strongholds from the Koudougou residency west and northwest of Ouagadougou in colonial times to the northeast of current day Ghana. Historically, these groups were subjects of the Mossi kingdoms. This area became in the late 1890s part of a three-way competition between the colonial forces of the French, the British, and the Germans, trying to subdue Djerma warlords and fight also the warlike local population who resisted fiercely to maintain its autonomy, while vying to occupy as much territory as possible at the expense of rival colonial powers.