This text examines the Tessera Paemeiobrigensis—a newly discovered bronze edict issued by Augustus in 15 BCE at Narbo Marcius—which reveals crucial historical, administrative, and legal dynamics of Roman Iberia. The imperial decree establishes fiscal immunity for the loyal Paemeiobrigenses while shifting their tax obligations onto the neighboring Allobrigiaecini following the Cantabrian Wars. Additionally, the inscription provides unprecedented epigraphic evidence confirming the existence of the ephemeral Transduriana provincia under the governance of L. Sestius Quirinalis. Beyond its provincial implications, the document directly attests to Augustus holding proconsular power alongside his tribunician authority in 15 BCE, challenging long-standing historiographical assumptions regarding the title's usage during the early Principate. Through combined paleographical, geographical, and legal analyses, the volume offers a preliminary assessment of tribal organization, imperial administration, and fiscal reform in the Iberian Northwest.