Every year, followers of the Nation of Islam celebrate the birth of its founder on Feb. 26. The holiday, known as Saviours’ Day, is commemorated by a three-day series of lectures, speakers and workshops in Chicago.

This year marks the 85th anniversary of the movement’s birth. Events were held on Feb. 20-Feb. 22, coinciding with the 50th anniversary of the death of Malcolm X, the civil rights leader who was assassinated when he was 39.

Malcolm was largely known as a spokesman for the Nation of Islam, a religious movement based on Islam. He joined the group after he was released from prison in 1952 and ministered at several temples including the largest one in Harlem in New York City. His influence led the group to grow from 400 members in 1952 to 40,000 in 1960.

He broke with the group shortly before his death on Feb. 21, 1965. Radical Nation of Islam members shot and killed Malcolm while he was speaking at a rally for Organization of Afro-American Unity, a more moderate group Malcolm X founded in 1964.

For those unfamiliar with the Nation of Islam and its beliefs, below are answers to four common questions about the organization.

1. What’s the history of the nation of Islam?

Wallace D. Fard, originally from Saudi Arabia, founded the Nation of Islam in 1930 in Detroit. He established a temple, the University of Islam and a corps of male guards called the Fruit of Islam that year. According to the group’s website, Fard preached that African-Americans belonged to “the Tribe of Shabazz from the Lost Nation of Asia,” who had been enslaved in America for more than three centuries.

“His mission was to teach the downtrodden and defenseless black people a thorough knowledge of God and of themselves and to put them on the road to self-independence with a superior culture and higher civilization than they had previously experienced,” the website states.

The group mixed the belief systems of Islam -- they read the Quran, worshipped Allah as their God and accepted Muhammad as their prophet -- with Black Nationalism. Fard believed that African-Americans should prepare for a race war and Christianity was a religion for slave owners. Members’ given names, which he believed originated during slavery, should be replaced with Arabic ones.

In June 1934, Fard reportedly disappeared in the woods. His followers believed he was an incarnation of Allah. Today, they celebrate his birthday, known as Saviours' Day, on Feb. 26.

The group was left to the leadership of Elijah Muhammad who advocated a more radical approach. He preached for the foundation of a separate state for African-Americans, advocated anti-white theology and called for adherence to a strict moral code.

At the time of Muhammad’s death on Feb. 25, 1975, the group had grown to 250,000 members. Afterward, the group fragmented. One faction was led by his son, Warith Deen Mohammed, who advocated for a more traditional approach to Islam. Louis Farrakhan, another Nation of Islam leader, did not like this direction and began his own version of the Nation of Islam based on Elijah Muhammad’s teachings.

Farrakhan remains the group’s leader to this day. He is a polarizing figure who comments on a variety of social issues, including the country’s government, educational system and urban communities.

One of his latest speeches, given on Dec. 1, encouraged his audience to “tear this goddamn country up,” referring to the shooting death of unarmed black teenager Michael Brown in Ferguson, Missouri. “You may not want to fight, but you better get ready. Teach your baby how to throw the bottle if they can, bite. We’re going to die anyway, let’s die for something,” he said.

The Nation of Islam does not state how many members it has. In 2007, Lawrence A. Mamiya, a professor of religion and African studies at Vassar College, told the New York Times he estimates there are 50,000 members. There are strong followings among the American prison population. There are several smaller chapters outside of the U.S. in England and the Caribbean.

2. How Was Malcolm X Involved In The Movement?

When Malcolm X was in prison from 1946 to 1952, he formed a relationship with Elijah Muhammad, and once he was released, he joined the Nation of Islam. He worked with Muhammad and became a leader of the group’s temples in Boston and New York. He also helped found new ones in Hartford, Connecticut, and Philadelphia and established the group’s newspaper, “Muhammad Speaks.”

Malcolm X was known for his militant rhetoric, famously saying “there's no such thing as a nonviolent revolution" and the need to remove the white racism “by any means necessary.” His proposals were seen as a radicalized version of Dr. Martin Luther King Jr.’s prescription for an integrated society through peaceful measures.

In 1963, Malcolm broke with the group after he learned Muhammad had committed extramarital affairs, fathering several children out of wedlock. The relationship was further strained when Malcolm X said the assassination of President John F. Kennedy was a demonstration of “chickens coming home to roost.”

Malcolm X formally left the group in 1964. He went on a pilgrimage to Mecca, where he converted to traditional Islam and adopted the name El-Hajj Malik El-Shabazz. He later founded the Organization of Afro-American Unity, a secular group that advocated for African-Americans.

3. What Are The Main Beliefs Of The Nation Of Islam?

On its website, the Nation of Islam says that it was founded “on the basis of peace” and that its mission is to answer “a prayer of Abraham to deliver his people who would be found in servitude slavery in the Western Hemisphere in this day and time.” The group said its logo adopts the Islamic crescent, moon and stars to symbolize universal peace and harmony.

“We have always been taught to respect the laws of the land. We are taught never to carry arms, to make war or to be the aggressor, for this is against the nature of the righteous. We are taught the Principles of Divine Unity and the Universal Brotherhood of Islam,” the website states.

The Southern Poverty Law Center has categorized the Nation of Islam as an extremist organization that promotes “deeply racist, anti-Semitic and anti-gay rhetoric.” It cites several speeches given by Farrakhan where he has called Adolf Hitler "a very great man" and Judaism a "dirty religion." Other prominent Nation of Islam leaders include Ashahed Muhammad who authored the book “The Synagogue of Satan,” in which he alleges that there is Jewish conspiracy to control the U.S. government.

On its website, the Nation of Islam continues to support the beliefs popularized by Elijah Muhammad, including the creation of a separate state for African- Americans.

“We believe that the offer of integration is hypocritical and is made by those who are trying to deceive the black peoples into believing that their 400-year-old open enemies of freedom, justice and equality are, all of a sudden, their ‘friends,’” Muhammad wrote. Other tenants include that African-Americans should be “freed from the names imposed upon him by his former slave masters” and that its followers “should not participate in wars which take the lives of humans” unless “America agrees to give us the necessary territory wherein we may have something to fight for.”

4. How Does It Differ From Islam?

The Nation of Islam and traditional Islam differ in fundamental ways. The former contends its founder Fard is an incarnation of God, something that defies traditional Islam’s view that there is only one true God, known as Allah. The two groups also diverge in terms of their prophets. In traditional Islam there are five prophets, three from the Hebrew Bible, Jesus and Muhammad. The Nation of Islam adds its second leader, Elijah Muhammad, to the list.

Perhaps the most striking difference stems from the two groups' approaches toward racial issues. The Quran states that Allah created mankind "from a single male and female, and made you into nations and tribes, so ye may know each other, not that ye may despise each other."

The Nation of Islam, on the other hand, contends that African-Americans and other nonwhites are superior to Caucasians. In one of its teachings, Elijah Muhammad said the white race appeared 6,000 years ago thanks to a selective breeding process by a black scientist named Yakub.