"Belém Tower (in Portuguese Torre de Belém) or the Tower of St Vincent is a fortified tower located in the Belém district of Lisbon, Portugal. It is an UNESCO World Heritage Site (along with the nearby Jerónimos Monastery) because of the significant role it played in the Portuguese maritime discoveries of the era of the Age of Discoveries. The tower was commissioned by King John II to be both part of a defense system at the mouth of the Tagus River and a ceremonial gateway to Lisbon.
The tower was built in the early 16th century and is a prominent example of the Portuguese Manueline style, but it also incorporates hints of other architectural styles. The structure was built from lioz limestone and is composed of a bastion and the 30 meter (100 foot), four story tower. It has incorrectly been stated that the tower was built in the middle of the Tagus and now sits near the shore because the river was redirected after the 1755 Lisbon earthquake. In fact, the tower was built on a small island in the Tagus River near the Lisbon shore.
History
In the late 15th century, King John II designed a defense system for the mouth of the Tagus River by building the Fortress of Cascais and the Fortress of São Sebastião of Caparica on the south side of the river. These fortresses did not completely cover the mouth of the river and further protection was required. King John II planned the tower to supplement the defense system and King Manuel I finished the construction of the tower after the death of King John II. Before the completion of the tower, the Grand Nau (Great Ship), a heavily armed, 1000 tonne (1100 ton) ship was used to supplement the defense. The construction of the tower completed the defense system and was finished in the last five years of Manuel's reign.
The tower was constructed between 1515 and 1521 by the military architect, Francisco de Arruda. Diogo de Boitaca, the first architect of the nearby Jerónimos Monastery, also participated in decorating the building. The tower was dedicated to the patron saint of Lisbon, St Vincent, and commemorated the expedition of Vasco de Gama.
Various guides claim the tower was built in the middle of the Tagus River and now sits near the shore after the 1755 earthquake redirected the river. But other references, including both the Portuguese Ministry of Culture and Institute of Architectural Heritage, state that originally the tower stood on a little island near the bank of the Tagus, opposite Restelo beach. As the shoreline progressively moved southward over the years, the tower is now nearly on the riverbank itself.
The tower was used as a fortress until 1580, when Lisbon was invaded by Spanish troops in the course of a struggle for the Portuguese throne. During subsequent centuries, the tower was mainly used as a political prison. King Miguel I (1828–34) used the damp dungeon to retain his liberal opponents. It has also been used as a custom house for ships entering Lisbon. The tower received military upgrades in 1589 and 1809–14.
In 1845, Queen Maria II restored the Belém Tower at the urging of romantic writer Almeida Garrett and the persuasion of the war minister, the Duke of Tercira. During the renovation, many neo-Manueline decorative elements were added to the building, including the battlements, the rampart walk and the niche of the Virgin. In 1907 it was declared a national monument.
The military quarters on the battlements were removed in 1940 when the Ministry of Finance took control of the tower. At that time an inner cloister was built. In 1983, an artificial lake was built around the tower to permanently surround it with water and an acrylic dome was built over the cloister. In that year it was named, together with the nearby Jerónimos Monastery, an UNESCO World Heritage Site. The two were named a joint UNESCO site because they are both considered masterpieces of the Manueline architectural style that represents the Portugal's era of exploration and its maritime discoveries that were influential to the modern world. The two specific UNESCO criteria these monuments meet are that they first are outstanding examples of an influential culture or civilization (the Portuguese exploratory age and maritime discoveries), and second, they are examples of a type of building or architectural style (Manueline) that illustrates a significant state in human history (the exploratory age).
The tower and bastion received maintenance and restoration from February 1997 to January 1998. These restoration works included reinforcing the structure, treating the mortar joints and structural cleaning. Structural works included the reinforcement of the south balcony supports with stainless steel rods and epoxy resin. The same was also carried out for fixing the statues of Saint Vincent and the Archangel Saint Michael. The tower was given a Europa Nostra award in 1999."
-- Source