The monumental stairway of 138 steps was built with French diplomat Étienne Gueffier’s bequeathed funds of 20,000 scudi, in 1723–1725, linking the Bourbon Spanish Embassy to the Holy See, today still located in Palazzo Monaldeschi in the piazza below, with the Trinità dei Monti above.

Following a competition in 1717 the steps were designed by the little-known Francesco de Sanctis,though Alessandro Specchi was long thought to have produced the winning entry. Generations of heated discussion over how the steep slope to the church on a shoulder of the Pincio should be urbanized preceded the final execution. Archival drawings from the 1580s show that Pope Gregory XIII was interested in constructing a stair to the recently-completed façade of the French church. Gaspar van Wittel's view of the wooded slope in 1683, before the Scalinata was built, is conserved in the Galleria Nazionale, Rome.

The Roman-educated Cardinal Mazarin took a personal interest in the project that had been in Gueffier's will and entrusted it to his agent in Rome, whose plan included an equestrian monument of Louis XIV, an ambitious intrusion that created a furore in papal Rome. Mazarin died in 1661, the pope in 1667, and Gueffier's will was successfully contested by a nephew who claimed half; so the project lay dormant until Pope Clement XI Albani renewed interest in it.
The Bourbon fleur-de-lys and Innocent XIII's eagle and crown are carefully balanced in the sculptural details. The solution is a gigantic inflation of some conventions of terraced garden stairs.