The honesta missio was the honorable discharge from the military service in the Roman Empire. The status conveyed particular privileges (praemia militiae). Among other things, an honorably discharged legionary was paid discharge money from a treasury established by Augustus, the Aerarium militare, which amounted to 12,000 sesterces until the Principate of Caracalla.
The honorably discharged legionary also presumably received a certificate after a service of approximately 20 to 26 years. Only a few, called tabulae honestae missionis, have been preserved, presumably because most were made of ephemeral materials.
Auxiliary soldiers, called peregrini (non-Roman citizens of the Empire), usually received along with an honesta missio Roman citizenship and conubium (permission to marry for themselves and their descendants. The imperial order about these grants were often documented on bronze military certificates, which might also include rights to cash and land, poll tax exemption for up to four people, and immunities from various duties. For example, recipients who desired to set up a business could receive a cash grant, and those desiring land could be given a sizable plot along with two oxen, cash, and 100 measures of assorted grains. These benefits would be reduced over time.
Other types of discharges included a premature discharge for health reasons (missio causaria) and a dishonorable discharge (missio ignominiosa).
The "gift" in Asterix and Caesar's Gift was a honesta missio.