The Church of St. Similien is an ancient church in Nantes. After the death of Bishop Similien in 310 AD, his successor, Eumilius, erected over his grave a votive chapel. One hundred years later, the bishop Leo, a Greek (444-458) built a real church to the site. In 848 AD, Nantes was vandalized during the Norman invasions. In 958 the restoration of the building began and was completed towards 1172 by the Duke Geoffroy II.
Following the siege of Nantes by Louis XI in 1487, Bishop Peter of Chaffault, repaired and enlarged the basilica Building it in the form of a Latin cross. The apse is Merovingian but the nave was extended towards the west, and flanked by two crosses.
During the French revolution, the church was closed to worship in 1793 and reopened after the Concordat of 1802. In 1824, the Millennium old building was destroyed and a church with three naves replaced it. The façade and portico were completed in 1835.
Fifteen years later, in 1850, the parish priest and the Church Council were considering the construction of a new church. In 1869, an architect, Eugene Boismen was appointed. The plans he offers were a Gothic building, inspired by those of the first half of the thirteenth century. The north-west facing building will include three naves, two ambulatory, bedside with a chapel which will be placed Our Lady of Mercy. The nave of five bays and end with a facade with two arrows. Permission to build the new church in 1872 is given. The Bishop Félix Fournier blessed the first stone of the new sanctuary on 5 October 1873. The work was completed in 1894 but as early as 1880, the vaults of the apse, the choir and transept were completed.
References:The Clementinum is a historic complex of buildings in Prague. Until recently the complex hosted the National, University and Technical libraries, the City Library also being located nearby on Mariánské Náměstí. The Technical library and the Municipal library have moved to the Prague National Technical Library at Technická 6 since 2009. It is currently in use as the National Library of the Czech Republic.
Its history dates from the existence of a chapel dedicated to Saint Clement in the 11th century. A Dominican monastery was founded in the medieval period, which was transformed in 1556 to a Jesuit college. In 1622 the Jesuits transferred the library of Charles University to the Klementinum, and the college was merged with the University in 1654. The Jesuits remained until 1773, when the Klementinum was established as an observatory, library, and university by the Empress Maria Theresa of Austria.