Ever hear the story about Jugurtha? He was a Numidian king (Numidia comprised modern-day Morocco and Algeria) who lived in 2 century BC and through an unfortunate series of events ended up being Rome's enemy.
Through a complex system of alliances and what would today be called "mission creep" the Romans ended up backing a rival claimant to his throne. And considering that at the time Rome was the sole superpower in the Mediterranean after eliminating Macedonia and Carthage, this was a literal death sentence for Jugurtha.
At the start of the next campaign season, a Consular army was raised in Rome and duly dispatched to Numidia to bring back Jugurtha's head.
As the Romans landed on Numidian shores, the hard pressed Jugurtha had a stroke of genius - Rome, being a republic at the time, awarded command of their armies to aspiring politicians who were supposed to compete in the next season's elections for the highest offices, field command and military glory being a prerequisite for consulship.
And since the election campaign was in full swing, even before the armies set sail, those aspiring politicians were heavily in red due to massive expenses for political lobbying - Roman politicians as a rule amassed ludicrous amounts of debt during the elections campaigns hoping to settle their debts either through plunder taken from their foes or by getting governorship of a very rich province.
That meant that Jugurtha wasn't dealing with Rome the superpower, but one very, very ambitious and broke Roman.
So Jugurtha, instead of facing the invincible Roman legions in the field (and certain death), simply called the Roman commander Memmius for a one-to-one meeting and casually offered to settle his debts and finance his campaign in exchange for turning a blind eye.
Memmius duly accepted, and returned to Rome after idling for months with his troops, claiming that he was "unable to force an engagement" with Jugurtha's forces.
This charade repeated itself for years, with every Roman commander coming back vastly richer, without engaging Jugurtha. Jugurtha grew so cocky that he even personally wrote a peace treaty with Rome and had it rubber stamped by the hapless Roman commander.
At the end, this was to prove Jugurtha's downfall - cockiness. On the occasion when he personally traveled to Rome as a witness for the prosecution against one of the former Roman commanders he bribed (!) he couldn't resist rubbing it in their faces that he was buying them off, shouting in the Senate "this entire chamber is for sale like a common whore".
And people who take bribes don't like being lectured from a position of moral superiority.
So the next Roman sent to deal with Jugurtha, the legendary Gaius Marius, refused to be bribed.