The name of the god Mithras appears in the name Mithridates, so Mithridates means something like "gift of Mithras." Mithridates is the form of the name the Romans used, although many spell the name Mithradates.
Mithridates VI (114- 63 B.C.) or Mithridates Eupator is the king who caused Rome so much trouble during the time of Sulla and Marius. Pontus had been awarded the title of friend of Rome, but because Mithridates kept making incursions on his neighbors, the friendship was strained. Pompey won his title "the Great" by defeating Mithridates.
The name Mithridates is associated with the gradual building up of tolerance to poison by ingesting a little bit each day. Mithridates, who ruled from 120-63, is said to have ingested a little bit of all the known poisons (a universal antidote) each day starting early in his life. The term mithridatium is now used for an antidote to poison.
From "Terence, this is stupid stuff," by A. E. Housman 1896
There was a king reigned in the East:
There, when kings will sit to feast,
They get their fill before they think
With poisoned meat and poisoned drink.
He gathered all that springs to birth
From the many-venomed earth;
First a little, thence to more,
He sampled all her killing store;
And easy, smiling, seasoned sound,
Sate the king when healths went round.
They put arsenic in his meat
And stared aghast to watch him eat;
They poured strychnine in his cup
And shook to see him drink it up:
They shook, they stared as white's their shirt:
Them it was their poison hurt
- I tell the tale that I heard told.
Mithridates, he died old.
Alternate Spellings: Mithradates
Sulla and Marius vie for forces to combat Mithridates.
Plutarch - Life of Lucullus
Lucullus was one of the Roman generals sent to defeat Mithridates.