Year 112 BC was a year of the pre-Julian Roman calendar

Roman calendar

The Roman calendar changed its form several times in the time between the founding of Rome and the fall of the Roman Empire. This article generally discusses the early Roman or pre-Julian calendars...

. At the time it was known as the Year of the Consulship of Drusus and Caesoninus (or, less frequently, year 642 Ab urbe condita

Ab urbe condita

Ab urbe condita is Latin for "from the founding of the City ", traditionally set in 753 BC. AUC is a year-numbering system used by some ancient Roman historians to identify particular Roman years...

). The denomination 112 BC for this year has been used since the early medieval period, when the Anno Domini

Anno Domini

and Before Christ are designations used to label or number years used with the Julian and Gregorian calendars....

 calendar era

Calendar era

A calendar era is the year numbering system used by a calendar. For example, the Gregorian calendar numbers its years in the Western Christian era . The instant, date, or year from which time is marked is called the epoch of the era...

 became the prevalent method in Europe for naming years.

Roman Republic

• Jugurtha
  Jugurtha
  Jugurtha or Jugurthen was a King of Numidia, , born in Cirta .-Background:Until the reign of Jugurtha's grandfather Masinissa, the people of Numidia were semi-nomadic and indistinguishable from the other Libyans in North Africa...
  
   declares war against the Roman Republic
  Roman Republic
  The Roman Republic was the period of the ancient Roman civilization where the government operated as a republic. It began with the overthrow of the Roman monarchy, traditionally dated around 508 BC, and its replacement by a government headed by two consuls, elected annually by the citizens and...
  
   (ends 105 BC
  105 BC
  Year 105 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Rufus and Maximus...
  
  ).