The Obelisco Sallustiano (13.91 m), which stands in front of the church of Santissima Trinità dei Monti, arrived in Rome in the third century. It is not known which emperor commissioned the obelisk, which is inscribed with hieroglyphs in very poor imitation of those of the Obelisco Flaminio, in Piazza del Popolo.
The obelisk originally stood in the Horti Sallustiani, the gardens of the historian Gaius Sallustius Crispus (86-35 BCE). The gardens, which covered a large area between the Porta Pinciana and the Porta Salaria, later became part of Villa Ludovisi.
At some point during the mists of time, the obelisk fell or was felled. In 1735 Pope Clement XII (r. 1730-1740) had it moved to Piazza di San Giovanni, where it lay for decades. It was finally erected in 1789, by order of Pope Pius VI (r. 1775-99), in front of the church of Santissima Trinità dei Monti.
There are three inscriptions on the base. The two short inscriptions read: III EIDVS / APRIL / ANNO M DCC / LXXXVIIII (The third day before the Ides of April.) and SACRI / PRINCIPATVS / EIVS / ANNO XV. (The fifteenth year of his pontificate.)
The longer inscription on the west face proclaims: PIVS VI PONT MAX / OBELISCVM / SALLVSTIANVM / QVEM PROLAPSIONE DIFFRACTVM / SVPERIOR AETAS / IACENTEM RELIQVERAT / COLLI HORTVLORVM / IN SVBSIDENTIVM VIARVM / PROSPECTV IMPOSITVM / TROPAEO / CRVCIS PRAEFIXO / TRINITATI AVGVSTAE / DEDICAVIT. (Pius VI, Pontifex Maximus, dedicated to the august Trinity the obelisk of Sallust, which, broken in its fall, a former age had abandoned prostrate, set atop the hill of the gardens in view of the streets below, and crowned with the victory trophy of the Cross.)