Part of a series on the
Military of ancient Rome 753 BC – AD 476
Structural history Army Unit types and ranks Decorations and punishments Legions Auxilia Generals Navy Fleets Admirals
Campaign history Wars and battles
Technological history Military engineering Castra Siege engines Triumphal arches Roads
Political history
Strategy and tactics Infantry tactics
Frontiers and fortifications Limes Walls Limes Britannicus Antonine Wall Hadrian's Wall Saxon Shore Limes Germanicus Alb Limes Lauter Valley Limes Lower Germanic Limes Main Limes Neckar-Odenwald Limes Upper Germanic-Rhaetian Limes Wetterau Limes Danube–Iller–Rhine Limes Norican Limes Claustra Alpium Iuliarum Pannonian Limes Limes Alutanus Limes Moesiae Trajan's Wall Anastasian Wall Limes Sarmatiae Limes Arabicus Limes Tripolitanus Limes Mauretaniae
Ancient Rome portal

Pia Fidelis, Latin feminine form for "pious and faithful", was the cognomen of several Roman legions, awarded by an emperor when the legion had proved "devoted and loyal". Some legions received this honour several times, and their name included the number of awards.

• Legio I Adiutrix Pia Fidelis Bis ("twice loyal and faithful")
• I Minervia Pia Fidelis Domitiana ("loyal and faithful to Domitian")
• II Adiutrix
• III Italica VII Pia VII Fidelis ("seven times faithful and loyal")
• V Macedonica VII Pia VII Fidelis
• VII Claudia VII Pia VII Fidelis ("seven times faithful and loyal")
• X Gemina Pia Fidelis Domitiana ("faithful and loyal to Domitian")
• XI Claudia Pia VI Fidelis VI ("six times faithful and loyal")