The House of Medici or de' Medici was a political dynasty, banking family and later royal house that first began to gather prominence under Cosimo de' Medici in the Republic of Florence during the late 14th century. The family originated in the Mugello region of the Tuscan countryside, gradually rising until they were able to found the Medici Bank. The bank was the largest in Europe during the 15th century, seeing the Medici gain political power in Florence — though officially they remained simply citizens, rather than monarchs.