QUEEN AMINA OF ZARIA

The seven original states of Hausaland: Katsina, Daura, Kano, Zazzau, Gobir, Rano, and Garun Gabas cover an area of approximately 1,300 square kilometres (500 sq mi) and comprise the heart of the Hausa realm. In the 16th century, Queen Bakwa Turunku built the capital of Zazzau at Zaria, named after her younger daughter. Eventually, the entire state of Zazzau was renamed Zaria, which is now a province and traditional kingdom in present-day Nigeria.
However, it was her elder daughter, the legendary Amina (or Aminatu), who inherited her mother's warlike nature. Amina was 16 years old when her mother became queen and she was given the traditional title of Magajiya, an honorific borne by the daughters of monarchs. She honed her military skills and became famous for her bravery and military exploits, as she is celebrated in song as "Amina, daughter of Nikatau, a woman as capable as a man."
Amina is credited as the architectural overseer who created the strong earthen walls that surround her city, which were the prototype for the fortifications used in all Hausa states. She subsequently built many of these fortifications, which became known as ganuwar Amina or Amina's walls, around various conquered cities.
The objectives of her conquests were twofold: extension of her nation beyond its primary borders and reducing the conquered cities to a vassal status. Sultan Muhammad Bello of Sokoto stated that, "She made war upon these countries and overcame them entirely so that the people of Katsina paid tribute to her and the men of Kano and... also made war on cities of Bauchi till her kingdom reached to the sea in the south and the west." Likewise, she led her armies as far as Nupe and, according to the Kano Chronicle, "The Sarkin Nupe sent her (i.e. the princess) 40 eunuchs and 10,000 kola nuts. She was the first in Hausaland to own eunuchs and kola nuts."
Amina was a pre-eminent gimbiya (princess) but various theories exist as to the time of her reign or if she ever was a queen. One explanation states that she reigned from approximately 1536 to 1573, while another posits that she became queen after her brother Karama's death, in 1576. Yet another claims that although she was a leading princess and de facto ruler, she was never a titular queen.
Despite the discrepancies in the tale of her life, one thing is certain, over a 34-year period, her many conquests and subsequent annexation of the territories conquered extended the borders of Zaria, which also grew in importance as a result and which became the center of the North-South Saharan trade and the East-West Sudan trade.