Mumadona Dias, or Muniadomna Díaz, was a Galician noble and Countess of Portugal, who ruled the county jointly with her husband from about c. 920 and then on her own after her husband's death around 950 until her death in 968. Celebrated, rich and the most powerful woman in the Northwest of the Iberian peninsula, she has been commemorated by several Portuguese cities.

Guimarães is a city and municipality located in northern Portugal, in the district of Braga. Its historic town centre has been listed as a UNESCO World Heritage Site since 2001, in recognition for being an "exceptionally well-preserved and authentic example of the evolution of a medieval settlement into a modern town" in Europe. The Nicolinas are the city's main festivities.