The Almohad Caliphate was a significant Islamic empire that emerged in the 12th century, primarily in North Africa and parts of the Iberian Peninsula. Founded by the Berber leader Ibn Tumart, the Almohads aimed to reform Islam by promoting a strict interpretation of the faith. They succeeded in uniting various tribes and territories under their rule, which included modern-day Morocco, Algeria, and parts of Spain. The Almohad Caliphate is known for its architectural achievements, including the construction of the famous Koutoubia Mosque in Marrakech. The empire reached its peak in the 12th and 13th centuries, but eventually declined due to internal strife and external pressures, leading to its fragmentation and the rise of rival powers.