Henry Swieca is a money man. The New York-based billionaire made his fortune by co-founding Highbridge Capital Corp., a hedge fund that boasted clients like the American International Group.

In 2009, the banking giant JP Morgan Chase, another client of Highbridge, fully took over the flagship hedge fund. Swieca went on to play a role at two more hedge funds: Talpion Fund Management, which he launched, and Clearline Capital, which Swieca joined as a startup investor in February 2013.

Swieca, whose net worth is $1.2 billion as of September 2013, is well-known as a financial guru. His every move is covered by the financial press. But he’s less known for what his foundation pours money into: right-wing, pro-Israel causes. Along with a host of charitable groups and domestic Jewish centers, the Swieca Family Foundation, which he runs with his Israeli-American wife Estee, has poured tons of cash into pro-Israel groups–including to religious extremist groups that operate in the most sensitive of holy places. Swieca did not return requests for comment on his donations.

According to tax records reviewed by AlterNet, Swieca, an Orthodox Jew, has given hundreds of thousands of dollars to the American Israel Education Foundation, the non-profit offshoot of the powerful lobbying group called the American Israel Public Affairs Committee. He’s also handed over cash to groups like the Friends of the Israel Defense Forces; the right-wing, anti-Muslim David Horowitz Freedom Center; and the Hebron Fund, a Brooklyn-based organization that funnels American money into illegal Israeli settlements in Hebron, a big city in the West Bank that has the most intense regime of settler violence and enforced segregation in the occupied Palestinian territories.

But perhaps most alarmingly is Swieca’s funding of the Temple Institute, an organization that promotes the building of the Third Temple on the third most holy site for Muslims. In early December, the Washington Post disclosed that Swieca and his wife funded the Jerusalem-based Temple Institute’s move to “to a large, renovated space in the Old City’s Jewish Quarter, overlooking the Western Wall.” The move put the institute just a short walk away from the place where they hope the Third Temple arises.

The religious extremists who run the Temple Institute have their sights set on the Haram al-Sharif, or the Noble Sanctuary in English, which is also the Temple Mount for Jews. “Our short-term goal is to rekindle the flame of the Holy Temple in the hearts of mankind through education,” the Temple Institute says on their website. “Our long-term goal is to do all in our limited power to bring about the building of the Holy Temple in our time.”

In the middle of the Noble Sanctuary sits the Dome of the Rock, a shrine whose gold dome is a fixture on the Jerusalem skyline. The Noble Sanctuary is home to the Al Aqsa Mosque, thought to be the place where the Prophet Muhammad was transported to from Mecca and is the third holiest site to Muslims around the world. At the same time, it is a site deeply revered by Jews, since it is the place thought to be where the First and Second Temples stood. The Second Temple was famously destroyed in A.D. 70 by the Romans, who then sent Jews into exile. The Temple Institute says that “the Temple Mount has to be cleared of the Dome of the Rock and the mosques which are presently located upon it before the physical rebuilding of the Holy Temple can begin.”

Both Judaism and Islam have competing claims to the site, making it the most contested piece of real estate on earth. In 2000, a provocative visit by Israeli Prime Minister Ariel Sharon to the Noble Sanctuary set off clashes that many say sparked the Second Intifada. It continues to be a frequent site of clashes between Palestinians and Israeli authorities.

Religious extremists on both sides frequently fan the flames of hatred around these holy sites, and any brash move could easily spark sectarian conflict in a combustible region. The Temple Institute, funded by Swieca and other private Jewish philanthropists, is one such Jewish extremist group that many say is acting dangerously. And despite being funded by the Israeli government to the tune of hundreds of thousands of dollars over the years, the Temple Institute has encouraged Israeli Jews to publicly challenge the prevailing legal arrangements that govern prayer on the Temple site, though the Israeli government seems to be slowly coming around to agreeing with the organization's goals.

This month, Israel reportedly asked Jordan, which administers the holy site, to consider allowing some level of Jewish worship, feeding into Palestinian fears that Israel wants to control all of Jerusalem forever instead of ceding the eastern half of it to a Palestinian state. Jordan rejected the request, with the director of the trust that controls the site saying that granting the request would spark “bloodshed."

Founded in 1984, the Temple Institute has been hard at work on a number of activities: recreating ritual objects to be used for a Third Temple; hosting conferences on research about the temple; educating the public and Israeli soldiers about its history; and lobbying for changes to the status quo that prohibits Israeli Jews from praying openly on the Noble Sanctuary’s/Temple Mount’s grounds. The organization, founded by a far-right religious zealot named Rabbi Israel Ariel, is also bolstered by the support of evangelical Christians, who provide the organization with much of their income through buying entrance tickets and museum shop items. Christian Zionists fully support the aims of the Temple Institute. They believe that the building of a Third Jewish Temple is a prerequisite to the coming of the Messiah and the apocalypse.

Ariel, a former Israeli soldier who helped capture Jerusalem’s Old City from Jordan during the 1967 War, leading to full Israeli control of Jerusalem (and the West Bank, Gaza, the Sinai and the Golan Heights), is a former member of the Kach party. Led by Rabbi Meir Kahane, the party was banned in Israel for its violent and racist rhetoric, which included advocating for the expulsion of all Arabs from the lands Israel controls. In 1984, members of a Jewish terrorist group were arrested by the Israeli police for plotting to blow up the Dome of the Rock. Ariel was one of the only people to speak out in support of their actions.

Today, the Temple Institute does not advocate for violence. Instead, they’re focused on changing the status quo that prevails at the holy site through other means. Those other means, though, are still considered dangerous and inflammatory. In the words of Israeli journalist Gershom Gorenberg, the author of a book that examines the struggle over the Temple Mount, the institute’s actions are “education for conflict over the world’s most contested holy site.”

The current arrangement at the Noble Sanctuary/Temple Mount dates back to the 1967 War. Although Israel had captured a site revered to Jews, they gave control of the Noble Sanctuary to the Jordanian-run Islamic waqf, a trust that controls access to the site, making it that rare area in Jerusalem where Israeli authorities don’t call all the shots. In 1921, members of Israel’s Chief Rabbinate crafted rules that prohibited Jews from entering the area. They said that Jews can only enter if they are ritually pure, but that the necessary purification ceremony is prohibited for various religious reasons. These rules were recently reaffirmed by the rabbinate. Jews are allowed to pray at the Western Wall, another holy place considered to be the wall outside the Temple Mount.

The legal prohibitions that surround the holy place haven’t stopped Jews who disagree from going to the Noble Sanctuary. In recent months, the Washington Post and the New York Times have highlighted the increasing numbers of Jews going up to pray on at the contested site. According to numbers published by an Israeli newspaper, the number of Jews visiting the holy site increased from 5,700 in 2009 to 8,300 in 2011. If Jews are found to be publicly praying, Israeli police take them away, with some being arrested. But some Jews try to pray discreetly.

The Temple Institute has been pushing Israeli Jewish prayer on the Temple Mount. In September, the organization teamed up with a right-wing movement called Manhigut Yehudit to lead tours at the site for the Jewish holiday of Sukkot.

The organization has been encouraged in recent months by a growing body of right-wing, expansionist Israeli legislators who share the Temple Institute’s goal in changing the prohibitions on prayer at the Noble Sanctuary/Temple Mount. In November, the HaBayit HaYehudi (Jewish Home) party, which promotes annexing 60 percent of the occupied West Bank, introduced a bill that would establish regular prayer areas for Jews on the holy site. On November 4, 2013, a heated debate in the Israeli Knesset broke out in response to proposed changes for prayer on the Noble Sanctuary/Temple Mount.

“When King David bought the Temple Mount you were savages in the desert. You have no rights on the Temple Mount, that’s a historical fact. Nothing will help you. Even now you are savages,” the Jewish Home’s Orit Strock told Palestinian Knesset members. In response, Balad’s Jamal Zahalka told her that she was “playing with fire.”

Another Palestinian legislator, Ahmed Tibi, warned that “the second intifada broke out because of Al Aqsa and the third intifada will break out because of you.”