The 'Porte Viennoise' was demolished at the beginning of the 19th century (1802-1810). It carried the inscription : DN IMP CAES CAIVS AVREL VALERIVS DIOCLETIANVS P F INVICTVS AVGVSTVS ET IMP CAESAR MARCVS AVREL VALERIVS MAXIMIANVS PIVS FELIX INVICTVS AVG MVRIS CVLARONENSIBVS CVM INTERIORIBVS AEDIFICIIS PROVIDENTIA SVA INSTITVTIS ADQVE PERFECTIS PORTAM VIENNENSEM HERCVLEAM VOCARI IVSSERVNT (CIL, XII, n° 2229) = “Our masters the Emperor Caesar Gaius Aurelius Valerius Diocletianus, pious, lucky, invincible august, and the Emperor Caesar Marcus Aurelius Maximianus, pious, lucky, invincible, august, thanks to whose foresight the walls of Cularo and the buildings within them were constructed, ordained that the Roman gate should be called 'Herculea'”.
« Altera porta qua Viennam ibatur a parte Isaræ Viennensis appellabatur. […] Cularonam postea muris et ædificiis Diocletianus et Maximianus imperatores restauraverunt, et portarum nomina mutaverunt, ac de suis agnominibus illas vocari jusserunt, ut duabus constat inscriptionibus quarum una est, ut sequitur, in porta Trojana, sub carcere Delphinali […].
Altera est in porta carceri Pontificali supposita, in hæc verba :
DD. NN. IMPP. CÆS. GAIVS AVREL. VALERIVS DIOCLETIANVS PP. INVICTVS AVGVSTVS ET IMP. CAESAR MARCVS AVREL. VALERIVS MAXIMIANVS PIVS FELIX INVICTVS AVG. MVRIS CVLARONENSIBVS CVM INTERIORIBVS AEDIFICIIS PROVIDENTIA SVA INSTITVTIS ADQVE (sic) PERFECTIS PORTAM VIENNENSEM HERCVLEAM VOCARI IVSSERVNT.
 Diocletianus enim Jovius, et Maximilianus (sic) Herculeus nominati fuerunt […], et litteris romanis hæ inscriptiones adhuc, quibusdam litteris corrosis, extant in eisdem portis, quæ fortem et elegantem structuram habent, grossisque et longis lapidibus sine calce sunt confectæ, ut liquido appareat eas Romanorum esse ædificium. Suntque eædem portæ antiquitate et pulchra lapidum congerie insignes, et in quolibet portarum latere est una turris non minoris elegantiæ et structuræ quam portæ ipsæ ; […]  Tandem huic divi Vincentii templo pontificalis Mariæ Virginis ædes adjuncta est, necnon et palatium episcopale, quod etiam portam illam Herculeiam amplectitur, et ideo recentiori vocabulo nunc porta Pontificalis vulgo dicitur ; et propter terræ et viæ elevationem  humi plus solito depressa est, et supra eam portam pontifices Gratianopolitani carcerem ædificaverunt. Itidem Delphini fecerunt supra portam Joviam. »
= “The other gate, by which one leaves for Vienne, is called the Isère-Vienne Gate. [...] Later, the emperors Diocletian and Maximian built the city walls and other buildings and changed the names of the city gates, giving them their agnomens, as is made clear by two inscriptions, the first of which, placed on the Trojan Gate, below the Delphinale Prison, reads as follows:
D. D. IMPP. CÆS. CAIVS AVREL. VALERIVS DIOCLETIANVS P. P. INVICTVS AVGVSTVS ET IMP. CÆSAR MARCVS AVREL. VALERIVS MAXIMIANVS PIVS FELIX INVICTVS AVG. MVRIS CVLARONENSIBVS CVM INTERIORIBVS ÆDIFICIIS PROVIDENTIA SVA INSTITVTIS ATQVE PERFECTIS PORTAM ROMANAM IOVIAM VOCARI IVSSERVNT.
[…] Diocletian's agnomen was Jupiter and Maximian's Hercules […]. These two inscriptions, written in Roman letters, though eroded, are still visible on the gates; these gates are solid and elegant; they are constructed with large and long stone blocks, without lime, and were manifestly built by the Romans. They are notable for the ancientness and the beauty of the stones they are built with; on the side of each gate stand towers not less elegant and finely built than the gates themselves […]. Finally, to the Church of St Vincent has been added a cathedral dedicated to the Virgin Mary and, likewise, an episcopal palace into which the Hercules Gate has been incorporated; this gate subsequently became known as the 'Bishop's Gate'. Later, the ground level and the road were raised and this gate was found too low, so the bishops of Grenoble constructed a prison on top of it; the dauphins similarly built a prison on the Jupiter Gate.”