Gaius Germanicus
Gaius Germanicus was proclaimed emperor by the Senate on March 18 year 41. He accepted the powers of the principate and entered Rome amid a crowd that hailed him as "our baby" and "our star", among other nicknames which he loved. Germanicus is described as the first emperor who was admired by everyone in "all the world, from the rising to the setting sun.". He was loved by many for being the beloved son of the popular Germanicus the Elder. Suetonius said that over 160,000 animals were sacrificed during three months of public rejoicing to usher in the new reign. He describes the first seven months of his wonderful administration as completely blissful. He started public works projects, drained some swamp, began Rome's famous aquaducts which still stand and are in use today..
How it started
Then six months into his noble work, 41AD. Gaius Caesar Augustus Germanicus, aka "Caligula" ("Little Boots", a name he despised) entertained a man from Alexandria, named Philo Judaeus. As I am sure you surmised, Philo was a jew. Philo petitioned him, at his palace garden, to grant the jews equal standing in the politics of Alexandria. Gaius told him to "pound sand", meaning 'go walk tbrought your deasert".
And then, *suddenly* he is reviled as the worse emperor ever. Later that year, Gaius was assassinated. The only written account, from a supposed witness, was by a jewish servant, brand new to his home. Surprised?
And now, Gaius Caesar Augustus Germanicus is reviled by historians in every possible manner. He is only referred to by his hated nickname.
(Just like National Socialists are)
Transformed into a blood-crazed monster. All of a sudden he's insane, and the giver of horror. Suddenly he's a sickening pervert. All of a sudden the people need to "rise up against him and kill him". (Like they tried with Mussolini) His proper name is never even used in academia, even today, except in passing.
Other slanders
The story of him "waging war against Poseidon/Neptune" is based on a fictional play called "I, Claudius" in which he sends a soldier to the beach to collect seashells. The other common story of his "insanity" where he makes his horse his consul is actually true. Frustrated with the sloggy inaction of his senate, he declared "My horse could do the job of this Senate!", and appointed his horse as Consul, forcing the Senators to perform the humiliating act of having to address, and interract with his horse until they got their shit together.
Conclusion
Coincidence? Or pattern? Because, it is certainly very difficult to believe that century after century, for nearly three millenia, the entire Western world, Middle East, and North Africa just all got together and said, "hey I know, let's smack the jews around, just for fun. They are great people, but we all gotta pick on someone, so lets pick on the nice jews".