The Duke of Coimbra is a noble title in Portugal, historically associated with the city of Coimbra. The title was first created in the 14th century and has been held by various members of the Portuguese royal family. The duke often played a significant role in the political and military affairs of the kingdom, especially during the period of the Portuguese Restoration War. The title is linked to the House of Aviz, which ruled Portugal during the late Middle Ages. The Duke of Coimbra is also known for its connection to the University of Coimbra, one of the oldest universities in Europe, which has been a center of learning and culture in Portugal for centuries.