The Notitia dignitatum et administrationum omnium tam civilium quam militarium (Latin for 'List of all dignities and administrations both civil and military') is a document of the Late Roman Empire that details the administrative organization of the Western and the Eastern Roman Empire. It is unique as one of very few surviving documents of Roman government, and describes several thousand offices The Notitia dignitatum et administrationum omnium tam civilium quam militarium (Latin for 'List of all dignities and administrations both civil and military') is a document of the Late Roman Empire that details the administrative organization of the Western and the Eastern Roman Empire. It is unique as one of very few surviving documents of Roman government, and describes several thousand offices from the imperial court to provincial governments, diplomatic missions, and army units. It is usually considered to be accurate for the Western Roman Empire in the 420s and for the Eastern or Byzantine Empire in the 390s. However, the text itself is not dated (nor is its author named), and omissions complicate attempts to ascertain its date from its content. The Notitia depicts the Roman army at the end of the 4th century AD. Therefore, its development from the structure of the Principate is largely conjectural because of the lack of other evidence. It was compiled at two different times. The section for the Eastern Empire apparently dates from c. 395 and that for the Western Empire from circa AD 420. Further, each section is probably not a contemporaneous "snapshot", but relies on data pre-dating it by as many as 20 years. The Eastern section may contain data from as early as AD 379, the beginning of the reign of Emperor Theodosius I. The Western section contains data from as early as c. 400: for example, it shows units deployed in Britannia, which must date from before 410, when the Empire lost the island. In consequence, there is substantial duplication, with the same unit of The Notitia dignitatum et administrationum omnium tam civilium quam militarium (Latin for 'List of all dignities and administrations both civil and military') is a document of the Late Roman Empire that details the administrative organization of the Western and the Eastern Roman Empire. It is unique as one of very few surviving documents of Roman government, and describes several thousand offices from the imperial court to provincial governments, diplomatic missions, and army units. It is usually considered to be accurate for the Western Roman Empire in the 420s and for the Eastern or Byzantine Empire in the 390s. However, the text itself is not dated (nor is its author named), and omissions complicate attempts to ascertain its date from its content. The Notitia depicts the Roman army at the end of the 4th century AD. Therefore, its development from the structure of the Principate is largely conjectural because of the lack of other evidence. It was compiled at two different times. The section for the Eastern Empire apparently dates from c. 395 and that for the Western Empire from circa AD 420. Further, each section is probably not a contemporaneous "snapshot", but relies on data pre-dating it by as many as 20 years. The Eastern section may contain data from as early as AD 379, the beginning of the reign of Emperor Theodosius I. The Western section contains data from as early as c. 400: for example, it shows units deployed in Britannia, which must date from before 410, when the Empire lost the island. In consequence, there is substantial duplication, with the same unit often listed under different commands. It is impossible to ascertain whether these were detachments of the same unit in different places simultaneously, or the same whole unit at different times. Also, it is likely that some units were merely nominal or minimally staffed. According to Roger Collins, "the Notitia Dignitatum was an archaising text written c. 425, whose unreliability is demonstrated by "the supposed existence of traditional (Roman military) units in Britain and Spain at a time when other evidence shows they were not there." The Notitia has many sections missing and lacunae within sections. This is doubtless due to accumulated textual losses and copying errors, because it was repeatedly copied over the centuries: the earliest manuscript possessed today dates from the 15th century. The Notitia cannot therefore provide a comprehensive list of all units that existed. The Notitia does not record the number of personnel. Given that and the paucity of other evidence of unit sizes at that time, the size of individual units and the various commands cannot be ascertained. In turn, this makes it impossible to assess accurately the total size of the army. Depending on the strength of units, the late 4th century army may, at one extreme, have equalled the size of the 2nd century force, i. e., over 400,000 men; and at the other extreme, it may have been far smaller. For example, the forces deployed in Britain circa 400 may have been merely 18,000 against circa 55,000 in the 2nd century. The Notitia contains symbols similar to the diagram which later came to be known as yin and yang symbol. The infantry units armigeri defensores seniores ("shield-bearers") and Mauri Osismiaci had a shield design which corresponds to the dynamic, clockwise version of the symbol, albeit with red dots, instead of dots of the opposite colour. The emblem of the Thebaei, another Western Roman infantry regiment, featured a pattern of concentric circles comparable to its static version. The Roman patterns predate the earliest Taoist versions by almost seven hundred years, but there is no evidence for a relation between the two.