Here are the four things you need to know about Trump’s deputy assistant and his ties to Hungary’s anti-Semitic far right.

1) Sebastian Gorka launched his own political party with prominent veterans of Jobbik, a far-right faction with a long history of anti-Semitism.

Gorka, whom Trump appointed as a top aide on January 20—the day of his inauguration—was born in London to Hungarian emigres who fled Communism. After the Communist Bloc’s fall in 1989, Gorka worked in Hungary for right-wing nationalist political leader Viktor Orbán, who is now prime minister. But Gorka left Orbán’s party and eventually launched his own faction in 2007 with two prominent former members of Jobbik, a party further to the right, with a history of anti-Semitism. In 2006, when Gorka’s political allies were still members of Jobbik, the party’s official online blog included articles such as “The Roots of Jewish Terrorism” and “Where Were the Jews in 1956?”, a reference to the country’s revolution against Soviet rule. One of his partners, Tamás Molnár, was Jobbik’s vice president during this time.

2) Gorka worked as press coordinator and advisor for an anti-government coalition co-led by an activist who called for expelling Jews.

In 2006, Gorka worked as a translator, press coordinator and advisor for the Hungarian National Committee, a coalition group whose four top leaders included László Toroczkai, head of the 64 Counties Youth Movement. In 2004, the Movement’s newspaper, which the government investigated for anti-Semitism, said of Jews, “We should get them out. In fact, we need to take back our country from them, take back our stolen fortunes. After all, these upstarts are sucking on our blood, getting rich off our blood.”

3) He wrote for a well-known anti-Semitic newspaper.

Between 2006 and 2007, Gorka wrote a series of articles in Magyar Demokrata, a newspaper known for publishing prominent anti-Semitic and racist Hungarian public figures. The newspaper’s editor-in-chief, András Bencsik, is notorious in Hungary for his own longstanding anti-Semitic views. In 1995, the Hungarian Jewish publication Szombat criticized Bencsik for writing that “the solid capital, which the Jews got after Auschwitz, has run out.” That same year, Szombat noted, Bencsik wrote in Magyar Demokrata, “In Hungary the chief conflict is between national and cosmopolitan aspirations.” “Cosmopolitan” in Hungarian society is generally a code word for Jews. In December 2004, the U.S. State Department reported bluntly to Congress that, “the weekly newspaper Magyar Demokrata published anti-Semitic articles and featured articles by authors who have denied the Holocaust.”

4) He defends the use of symbols adopted by World War II era Hungarian Nazis and collaborationists as still valid symbols of nationalism.

Gorka’s affinity for Hungarian nationalist and far-right ideas first came to the American public’s attention when Eli Clifton of the news website Lobelog noticed from a photograph that Gorka had appeared at a Trump inauguration ball wearing a Hungarian medal known as Vitézi Rend. The medal signifies a knightly order of merit founded in 1920 by Admiral Miklos Horthy, Hungary’s anti-Semitic ruler and Hitler’s ally during World War II. Notwithstanding this alliance, many within Hungary’s right revere Horthy for his staunch nationalism during the overall course of his rule from 1920 to 1944. In 2006, Gorka also defended the use of the Arpad flag, which Hungary’s murderous Arrow Cross Party used as their symbol. The Hungarian Arrow Cross Party killed thousands of Jews during World War II, shooting many of them alongside the Danube River and throwing them into the water. Gorka told the news agency JTA at the time that “if you say eight centuries of history can be eradicated by 18 months of fascist distortion of symbols, you’re losing historic perspective.”

4 Things You Need To Know About Trump’s Aide’s Ties To Hungary’s Far Right