Donativum was the name given to the gifts of money dispersed to the soldiers of the Roman legion

Roman legion

A Roman legion normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. The organization of legions varied greatly over time but they were typically composed of perhaps 5,000 soldiers, divided into maniples and later into "cohorts"...

s or to the Praetorian Guard

Praetorian Guard

The Praetorian Guard was a force of bodyguards used by Roman Emperors. The title was already used during the Roman Republic for the guards of Roman generals, at least since the rise to prominence of the Scipio family around 275 BC...

 by the Roman Emperor

Roman Emperor

The Roman emperor was the ruler of the Roman State during the imperial period . The Romans had no single term for the office although at any given time, a given title was associated with the emperor...

s.

The purpose of the donativa varied: some were expressions of gratitude for favors received, and others out right bribery for favors expected in return. Donativa were normally rendered at the beginning of each new emperor's reign. During the 2nd and 3rd centuries, this form of bribery became a crucial part of any successful ruler in Rome. Such was the case with many of the soldier-emperors from 235

235

Year 235 was a common year starting on Thursday of the Julian calendar. At the time, it was known as the Year of the Consulship of Severus and Quintianus...

 to 248

248

Year 248 was a leap year starting on Saturday of the Julian calendar. At the time, it was known as the Year of the Consulship of Philippus and Severus...

. The Praetorian Guard, intimate to the emperor's person, was an even greater threat to security. The cohorts stationed in Rome were difficult to appease and quick to commit assassination. The donativum thus provided a terrific way to purchase the Guards' support and loyalty.

Emperor Augustus

Augustus

Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

 bequeathed the Praetorian Guard a substantial sum in his will, but it was not until Tiberius' reign that gifts of money were thought mandatory. The Praetorian Guard received such gifts for turning a blind eye when Sejanus

Sejanus

Lucius Aelius Seianus , commonly known as Sejanus, was an ambitious soldier, friend and confidant of the Roman Emperor Tiberius...

, their prefect, fell from power. Each Praetorian Guard received 10 gold pieces for refraining from defending Sejanus's. In 41, after the assassination of Caligula

Caligula

Caligula , also known as Gaius, was Roman Emperor from 37 AD to 41 AD. Caligula was a member of the house of rulers conventionally known as the Julio-Claudian dynasty. Caligula's father Germanicus, the nephew and adopted son of Emperor Tiberius, was a very successful general and one of Rome's most...

, the Guard supported Claudius

Claudius

Claudius , was Roman Emperor from 41 to 54. A member of the Julio-Claudian dynasty, he was the son of Drusus and Antonia Minor. He was born at Lugdunum in Gaul and was the first Roman Emperor to be born outside Italy...

, and after a brief time the Senate learned that the Guard had installed him on the throne. Claudius gave them 150 gold pieces, or some 3,750 denarii

Denarius

In the Roman currency system, the denarius was a small silver coin first minted in 211 BC. It was the most common coin produced for circulation but was slowly debased until its replacement by the antoninianus...

, to which the senators' 100 sesterces

Sestertius

The sestertius, or sesterce, was an ancient Roman coin. During the Roman Republic it was a small, silver coin issued only on rare occasions...

 were added annually to commemorate Claudius's accession. The inevitable result of the custom of the donativum was the Praetorians' auctioning of the Empire to Didius Julianus

Didius Julianus

Didius Julianus , was Roman Emperor for three months during the year 193. He ascended the throne after buying it from the Praetorian Guard, who had assassinated his predecessor Pertinax. This led to the Roman Civil War of 193–197...

in 193.

Imperial Donativa to the Praetorian Guard 14 - 193
Year	Emperor	Provocation	Denarii
14	Augustus	Last will	250
31	Tiberius	Loyalty in Sejanus crisis	1,000
37	Caligula	Upon accession	500
41	Claudius	Upon accession	3,750
Annually	Claudius	Anniversary of accession to the throne	25
54	Nero	Accession	3,750
		Pay for assassinations	500 or less
69	Galba	Promised by Nymphidius Sabinus, but not paid	7,500
69	Otho	Promised	1,250
69	Vitellius	Promised	1,250
69	Vespasian	Regular donativum	unknown
79	Titus	Regular donativum	unknown
81	Domitian	Considered doubling the donativum but opted for regular sum	unknown
96	Nerva	Regular donativum	unknown
98	Trajan	Regular donativum	unknown
117	Hadrian	Double normal sum	unknown
138	Antoninus Pius	Regular donativum and upon daughter's marriage	unknown
161	Marcus Aurelius	Joint rule vith Verus	5,000
180	Commodus	Regular donativum; second promised but unpaid	unknown
193	Pertinax	Forced to pay donativum of Commodus	3,000
193	Didius Julianus	Purchased the throne	7,250
193	Septimius Severus	Promised a donativum but paid less	250