The project to build the Sacré-Cœur Basilica (Basilica of the Sacred Heart) was initiated by a group of influential people. Their reasons to build this monument were two-fold: they had pledged to build a church if Paris escaped unscathed from the war with the Prussians, and they saw the defeat of the French at the hands of the Prussian army in 1870 as a moral condemnation of the sins of Paris.
The project was authorized by the National Assembly in 1873, and a competition was organized. The goal was to build an imposing basilica true to Christian traditions.The winner of the competition was Paul Abadie, who had already restored two cathedrals in France. He designed an immense basilica in a Roman-Byzantine style. This architectural style stands in sharp contrast with other contemporary buildings in France, which were mostly built in a Romanesque style.Construction of the Basilica started in 1876 with Abadie as the lead architect. When Paul Abadie died in 1884, he was succeeded by Lucien Magne, who added an 83-meter-tall (272 ft.) clock tower.