Zamora straddles the Douro River. The Romans named the settlement "Occelum Durii" ("Eye of the Duero"). For the Visigoths, the place was "Semure".

In the 710s the town was conquered and a Berber garrison was left in there, but some decades later it was seized by Alfonso I of Asturias. A diocese was established in the town in the early 10th century. Ibn al-Qitt unsuccessfully tried to invade the city in 901, Almanzor eventually seized the city in 966. The place returned to Christian control during the reign of Alfonso V of León.

Since the early 11th century the place saw planned repopulating efforts. City walls were also erected in the 11th century. The most notable historical episode in Zamora was the assassination outside the city walls of the King Sancho II of Castile in 1072. Ferdinand I of León had divided his kingdoms between his three sons. To his daughter Urraca, he had bequeathed Zamora. All three sons warred among themselves, till the ultimate winner, Sancho, was left victorious. Zamora, under his sister who was allied with Leonese nobles, resisted. Sancho II of Castile, assisted by El Cid, laid siege to Zamora. King Sancho II was murdered by Bellido Dolfos, a duplicitous noble of Zamora, Bellido Dolfos. After the death of Sancho, Castile reverted to his deposed brother Alfonso VI of León.

The water mills were donated in 1157 by King Alfonso VII to the cathedral chapter of the diocese of Zamora. They were in operation until the beginning of the 20th century. The complex consists of four buildings, three of which were in the river and mills were powered by water wheels.