The Scalinata della Trinità dei Monti, much better known as the Spanish Steps, was designed by two little-known Roman architects, Francesco de Sanctis (1679-1731) and Alessandro Specchi (1668-1729), and built between 1723 and 1725. The steps were financed by a French diplomat, Étienne Gueffier (1573-1660), who left an amount of money in his will expressly for this purpose.
The 136 steps, which link the Piazza di Spagna with the church of Santissima Trinità dei Monti, rise in three distinct flights, a clear reference to the Holy Trinity.
The four stone balls, which stand at the base of the steps, are alternately decorated with the fleur-de-lys of the French monarchy and the heraldic eagle of the coat of arms of Pope Innocent XIII (r. 1721-24).
The steps sport two long inscriptions. The inscription on the lower landing reads: D O M / MAGNIFICAM HANC SPECTATOR QVAM MIRARIS SCALAM / VT COMMODVM AC ORNAMENTVM NON EXIGVVM / REGIO COENOBIO IPSIQ VRBI ALLATVRAM / ANIMO CONCEPIT LEGATAQ SVPREMIS IN TABVLIS PECVNIA / VNDE SVMPTVS SVPPEDITARENTVR CONSTRVI MANDAVIT / NOBILIS GALLVS STEPHANVS GVEFFIER / QVI REGIO IN MINISTERIO DIV PLVRES APVD PONTIFICES / ALIOSQVE SVBLIMES PRINCIPES EGREGIE VERSATVS / ROMAE VIVERE DESIIT XXX JVNII MDCLXI / OPVS AVTEM VARIO RERVM INTERVENTV / PRIMVM SVB CLEMENTE XI / CVM MVLTI PROPONERENTVR MODVLI ET FORMAE / IN DELIBERATIONE POSITVM / DEINDE SVB INNOCENTIO XIII STABILITVM / ET R P BERTRANDI MONSINAT TOLOSATIS / ORD MINORVM S FRANCISCI DE PAVLA CORRECTORIS GENLIS / FIDEI CVRAEQ COMMISSVM AC INCHOATVM / TANDEM BENEDICTO XIII FELICITER SEDENTE / CONFECTVM ABSOLUTVMQUE EST / ANNO IVBILEI M DCC XXV (To God, the Best and the Greatest. Etienne Gueffier, a noble son of France, who passed to his reward at Rome on June 30th 1661 after long and distinguished employment in the royal service, at the court of many pontiffs and other lofty princes, conceived in his mind this grand stairway at which you marvel, onlooker, as an object destined to lend no small convenience and embellishment to the royal cloister and the city itself. And with a bequest of money in his last will whereby the cost should be defrayed, instructed that it be built. Owing to sundry interruptions, the work, first mooted under Clement XI, when many plans were proposed, then decided under Innocent XIII and entrusted to the good faith and care of the Reverend Father Bertrand Monsinat of Toulouse, Corrector General of the Friars Minim of St Frances of Paola, and finally begun during the happy reign of Benedict XIII, was completed in the year of the Jubilee, 1725).
The inscription on the upper landing reads: D O M / SEDENTE BENEDICTO XIII / PONT MAX / LUDOVICO XV / IN GALLIIS REGNANTE / EIUSQ APUD SANCTAM SEDEM / NEGOTIIS PRÆPOSITO / MELCHIORE S R ECCLESIÆ / CARDINALI DE POLIGNAC / ARCHIEPISCOPO AUSCITANO / AD SACRÆ ÆDIS ALMÆQUE URBIS / ORNAMENTUM / AC CIVIUM COMMODUM / MARMOREA SCALA / DIGNO TANTIS AUSPICIIS OPERE / ABSOLUTA / ANNO DOMINI MDCCXXV (To God, the Best and the Greatest. During the reign of Benedict XIII, Pontifex Maximus, and Louis XV of the French, and while Melchior de Polignac, Archbishop of Auch, Cardinal and of the Holy Roman Church, was in charge of the affairs of the Holy See, the marble stairway was completed for the embellishment of the sacred church and of the kindly city and for the convenience of the citizens, with the workmanship worthy of such great patronage, in the year of the Lord, 1725).
In spring the Spanish Steps are adorned with dozens of terracotta pots full of azaleas.