The gens Didia, or Deidia, as the name is spelled on coins, was a plebeian family at ancient Rome, which first appears in history during the final century of the Republic.
Titus Didius obtained the consulship in 98 BC, a dignity shared by no other Didii until imperial times.
[4] Anthony Birley suggests they came from eastern Italy, "specifically from the coastal town of Histonium.
[6] The earlier Didii used the praenomina Sextus, Titus, and Gaius, to which later members of the family added Quintus, Aulus, and Lucius.
This cognomen, referring to a cockerel, belongs to an abundant class of cognomina derived from the names of everyday objects and animals.