Samuel Ball Platner, Thomas Ashby, A Topographical Dictionary of Ancient Rome

ARCUS PIETATIS

*mentioned only in the Mirabilia (23) and the Anon. Magl. It stood on the north side of the Pantheon, perhaps in the line of the enclosing porticus. Hulsen (RAP ii. 19; cf. HCh 437) places it close to the church of the Maddalena, connecting it with the wall enclosing the precinct of the TEMPLUM MATIDIAE (q.v.). Rushforth (JRS 1919, 37-40, 53-54) conjectures that it is the arch of Augustus described in the twelfth century by Magister Gregorius as bearing the inscription 'ob orbem devictum Romano regno restitutum et r. p. per Augustum receptam populus Romanus hoc opus condidit,' and mentioned by Dio Cassius (li. 19) as decreed to be set up in the forum in 29 B.C. (but not actually erected) and afterwards placed here. The inscription, though it cannot be a literal transcript, may be the echo of a genuine one (see ARCUS AUGUSTI). A relief on this arch is said (Anon. Magl.) to have represented a woman asking a favour of Trajan,¹ and about this scene a legend was woven, one form of which appears in Dante (Purg. x. 73 ff.). This arch cannot be identified with any of those known to us from other sources (AJA 1904, 34; HJ 590; Boni in Nuova Antologia, 1st Nov. 1906, 36).