The Basilica of the Sacré-Coeur de Montmartre is a minor basilica, and expiatory temple and shrine of Eucharistic adoration, located on the hill of Montmartre, in Clignancourt, the 18th arrondissement of Paris.

Its construction was decided by the National Assembly in 1873 as a religious building in perpetuity to honour the memory of the many French citizens who had lost their lives during the Franco-Prussian War, but its promoters were accused from the outset of also erecting it to atone for the sins of the Paris Commune.

A competition was organised to choose the architect who would design it, and it was the architect Paul Abadie who won the competition for its construction. The foundation stone was laid in 1875, and although it was completed in 1914, it was not consecrated until the end of World War I in 1919. The church was built with funds exclusively from a popular subscription, and is now one of the most visited monuments in the Ville Lumière.

Montmartre has long been a place of worship, first as a Druidic site of Gaulish paganism, then Gallo-Roman temples were built in honour of Mercury, and probably Mars; then in the 3rd century, after the martyrdom of Saint Denis, the Crypt of the Martyrdom of Saint Denis was built. In the 7th century, the church of Saint-Pierre de Montmartre, one of the oldest in Paris, was built for the Royal Abbey of Montmartre by King Louis VI and his wife Adelaide of Savoy.

In the context of 18703 during the Franco-Prussian war, and the approach of Messrs Alexandre Legentil and Hubert Rohault de Fleury is spiritual, they promise to build a church consecrated to the Sacred Heart of Jesus, "in reparation" (i.e. in penance for infidelities and sins committed) because for them, the misfortunes of France stem from spiritual rather than political causes.

In a letter addressed to the priests of his bishopric of Nantes on 4 September 1870, the day of the declaration of the Third Republic, Archbishop Felix Fournier attributed France's defeat in the Franco-Prussian war of 1870 to divine punishment after a century of moral decadence since the Revolution of 1789.

In November 1870, M. Beluze, a member of the General Council of the Saint-Vincent-de-Paul Conferences in Lyon, wrote to Adolphe Baudon (1819 - 1888), general president of these Conferences, to inform him of the Lyonnais' vote and to suggest a similar vote for Paris. The latter proposed a campaign to the Universe, the newspaper of Louis Veuillot (1813 - 1883), which from 13 December launched the suggestion of a building on the Montmartre hill. At the beginning of December, Mr Baudon, in turn, wrote to his right-hand man Alexandre Félix Legentil (1821 - 1889), a member of the General Council of the same society, who had taken refuge in Poitiers because of the war, to present him with the idea, proposing that the new church be dedicated to the Virgin. The latter welcomed the proposal with enthusiasm, but suggested to his president that the shrine be dedicated to the Sacred Heart. The latter, as well as the other members of the General Council of the Society of Saint-Vincent-de-Paul, were reluctant to change this term, fearing that devotion to the Sacred Heart was not yet sufficiently widespread. habits of piety of the French: it was difficult to raise the necessary funds for the construction of this new shrine. On 8 December 1870, Alexandre Félix Legentil, who in the meantime had become aware of Father de Boylesve's pamphlet, informed the latter of the letter he had recently received.