The Dominate is the name historians give to the later Roman Empire, from about AD 284 under Diocletian. The emperor was addressed as dominus, lord, and ruled more openly as a master. Many scholars now think the split from the Principate is overdrawn.
Key takeaways
- The Dominate starts conventionally with Diocletian around AD 284 and follows the Principate.
- The word dominus first meant slave-owner, and became a title for the emperor.
- Our map covers the Dominate from AD 395, when the empire is shown with 42 provinces and an area of 4.72 million km².
- Since the early 20th century many scholars have rejected the idea of a sharp break, and the term is now rarely used as a model.
How the Dominate works
The Dominate is a label for the later Roman Empire, traditionally counted from the reign of Diocletian around AD 284 [1]. It is the second half of a two-part division of imperial history, after the Principate, which began with Augustus in 27 BC [1].
The name comes from dominus, a Latin word meaning lord or master. It first meant the owner of slaves, and over time it became a title for the emperor [1]. One coin legend, domino et deo nato, is translated as "born to be lord and god" [1]. The idea is that early emperors acted as first citizens, while later ones ruled openly as lords.
The German historian Theodor Mommsen, who introduced the two terms in the 19th century, saw the Principate as imperial authority sitting inside Republican institutions, and the Dominate as a break in which the emperor became the state [1][2]. Court ritual is often given as evidence. Diocletian is said to have introduced genuflection before the emperor, a move towards Eastern practice [1].
Many scholars have since moved away from the idea. Since the early 20th century, historians have increasingly rejected a break around Diocletian. One argued in 1978 that there was no real constitutional change, and that both terms fit badly as strict periods [1]. The Oxford Classical Dictionary calls "dominate" a near-obsolete term [1]. So it is best used as shorthand for a later style of rule, and not as a date at which Rome suddenly changed.
What did change in this period is easier to point to: a reformed government, smaller provinces, and the splitting of the empire into regions run by more than one ruler. See the tetrarchy for the first of these, and East and West for what followed.
An example from our data
The Dominate stretches over the later part of the slider. At AD 395 the empire is shown at about 4.72 million km² with 42 provinces, coloured purple in the East and orange in the West. At AD 476 the Western half has shrunk to about 1.94 million km², with 19 provinces. The Eastern empire carried on, as the Byzantine Empire page explains.
One caution: the map's province outlines are those of AD 200, before Diocletian's reforms. Later provinces, dioceses and prefectures are not drawn, so the map shows the lands but not the later way they were governed. Each date's outline method is given on its year page. The years page lists them all.
The thing people get wrong
The mistake is to treat the Dominate as a clean second act that begins the day Diocletian becomes emperor. Augustus's successors had already used grand titles and some had been worshipped as gods, and Diocletian's court did not erase the Senate or the old offices overnight [1]. The label comes from modern writers, and Romans did not know they were living in a "Dominate". The most careful way to use the word is to say that rule became more openly monarchic over time.
Dominate vs Principate
| Principate | Dominate | |
|---|---|---|
| Conventional dates | 27 BC to AD 284 | From about AD 284 |
| Emperor's title | Princeps, first citizen | Dominus, lord |
| Mommsen's view | Authority inside Republican forms | The emperor becomes the state |
| Modern view | A useful label | Rarely used as a model |
Frequently asked questions
What does dominus mean?
Lord or master. It first meant the owner of slaves and later became a title used for the emperor.
When did the Dominate start?
Conventionally with Diocletian, around AD 284. It is a convenient label and not a clear event.
Is the Dominate still used by historians?
Rarely. It is often called a near-obsolete term, and most scholars no longer see a sharp break at Diocletian.
Sources
- Dominate, Wikipedia.
- Principate, Wikipedia.
- Roman Empire, Wikipedia.
- Every figure from our own map is worked out from the datasets on the data sources page (checked against Ancient World Mapping Center outlines and Pleiades).