A standard Roman military diploma consists of two bronze plaques bound together on both sides and sealed with wax by seven witnesses. The front cover contained a copy of the complete text also repeated on the two interior leafs. The back cover contained the names of seven witnesses who sealed the diploma. These diplomas are actually copies of original bronze documents that were kept in an archive in Rome. The copies were distributed to a serviceman upon his retirement as proof of his honorable service and newly acquired citizenship (at the end of a minimum twenty-five year military service, citizenship was awarded to the soldier and wife and children). The text was repeated twice, on the outside and on the inside, to prevent fraud since the sealed interior text could not be tampered with. If a former soldier enjoying retirement on the Dalmatian coast was suspected of forging the cover of his diploma, local government officials could break the seals and verify that the interior text corresponded to the front cover without having to wait for confirmation from the archives in distant Rome. Today, Roman military diplomas are beloved by scholars because they contain of wealth of information that can be precisely dated. Through such records, it is possible to track the deployment of troops throughout the empire and to chart the rise in rank of specific individuals. Likewise, in the life of a specific soldier, we can determine where he was born, raised, what wars he fought in, and where he retired to.

This bronze plaque is the second half of a military diploma, featuring finely incised Latin inscription on both sides. The front of this plaque corresponds to the second half of the detailed interior text while the back lists the name of the seven witnesses. The text names the recipient of this diploma as Cersus, a cavalryman who served in the First British Cavalry Unit for over twenty five years. This regiment was an auxiliary unit of the 15th Legion Apollinaris; therefore, it is likely that Cersus fought in the Jewish War and witnessed the destruction of the Second Temple in 70 A.D. From the dating of the consuls in the surviving portion of the text, it is possible to surmise from other contemporary diplomas what the text on the missing plaque likely would have said: “Emperor Caesar Vespasian Augustus, Chief Priest, holder of the power of the tribune for the fourth time, hailed as general for the eighth (7) time, father of his country, consul for the third time, designated as consul for the fourth time. For the cavalry men and foot soldiers, who have served in cavalry units and foot units, who have served for twenty-five or more years, whose names are written below, to them and their children...”. The inscription on the front of this plaque completes the text as such, “...are granted citizenship and legitimate marriage with the women they have at the time of the grant of citizenship or if they are not married, with whom they later marry, provided only one woman per man. Three days before the calends of August, the consuls being L. Flavius Fimbria and C. Atilius Barbarus. First British Cavalry Unit, commanded by M. (son of M.) Coelius Sergia Honoratus, to the cavalry trooper Cersus, son of Denturasadus, a Thracian. Copied and checked against the bronze tablet which is put up in Rome on the Capitolium at the Julian family altar in front of the balcony." The names of the seven witnesses listed on the reverse are: "L. Lucci Atratini; L. Aviiani Saturnini; C. Aponi Firmi; Sex. luli Proculi; C. Titi Recepti; Cn. Cetroni Verecundi; M. Faltoni Fortunati, Centurion of the 15th Legion Apollinaris."
This bronze military diploma, issued to the valiant Cersus, today stands as a memorial to the life of this otherwise forgotten soldier. Furthermore, it is a testament to the military might of Rome and the sophisticated bureaucracy that made it possible to administer such a large army over such a large empire.

Surely this item is of great interest and must be referred to an expert.
Vespasian is present at the invasion of Britain in 43 and was emperor from 69 AD to 79 AD.
He was consul for the third time in 71 AD and for the fourth time in 72 AD. This inscription dates to 71-72 AD. Was this auxilliary alae raised at this time? This is exceptionally early for the raising of a British unit, cavalry, infantry, any British auxiliary unit. No scholar has postulated British auxiliary units at such an early date.
So either:
a. "First British Cavalry Unit" is a an epithet given to another unit because they served in Britain. This happened often for military units and people, with epithets such as "Britanicus", "Germanicus", "Hispana" not referring to the home of the person or people honoured;
b. This really is the "First British Cavalry Unit". If so, this is a cracking find.

A British auxilliary alae raised in 46? Or Vespasian's colleagues honoured on his ascension to emperor?