Democratic presidential candidate Hillary Clinton often brings up the inspiring story of her mother, Dorothy Howell Rodham, noting during her victory speech in Brooklyn on June 7th that her mom told her to stand up to bullies. Clinton’s father, Hugh E. Rodham, is rarely mentioned throughout the former secretary of state’s campaign.

As observed by The New York Times, even Clinton’s Father’s Day message last year had more to do with her mother than her father.

So who exactly was Hillary Clinton’s dad, and why might she be reluctant to speak of him? Here are five fast facts you need to know.

1. He Was a Staunch Republican

Hugh E. Rodham likely would have had mixed feelings about his daughter becoming the Democratic nominee for president, as he was a lifelong Republican with an ingrained hatred for those on the other side of the aisle. In her autobiography, Clinton describes her father as a “rock-ribbed, up-by-your-bootstraps, conservative Republican and proud of it.”

In fact, Rodham was particularly enthusiastic about Barry Goldwater’s 1964 presidential campaign. Some of her father’s beliefs rubbed off on Clinton, who was an active Young Republican growing up and later a Goldwater Girl. Clinton says she liked Goldwater because he was “a rugged individualist who swam against the political tide.” Clinton began to stray from the Goldwater camp by the end of high school, though, and while at Yale she became a liberal Democrat. In 1972, Clinton began working for George McGovern’s presidential campaign.

But Rodham stood firm in his Republican beliefs his whole life, and he was highly skeptical about his daughter marrying Bill Clinton, a Democrat. Until the end of his life, Rodham always hoped that his new son-in-law would change his mind and join him in the Republican party, according to CNN.

Hillary Clinton has cited this side of her father as an example of how she can reach out to those in the other party. She once said that her dad taught her that “a person was not necessarily bad just because you disagreed with him.”

2. He Was an Extremely Strict Father

Hillary Clinton draws scrappy determination from a tough, combative father. http://t.co/oNm4ANxY7d via @amychozick pic.twitter.com/dMU5vZUYKL — NYT Politics (@nytpolitics) July 21, 2015

Rodham is said to have severely disciplined all three of his children, creating a rather strict environment at home. According to The New York Times, he often excessively spanked his kids in order to keep them in line, and an adviser to Clinton described him as “kind of a tough customer.”

Maybe this was for the best, though, as many of Clinton’s aides say that this helped shape her into the tough fighter she is today and that Rodham represents Clinton’s combative, determined side.

“He was such a force in the family, and there’s a lot of him in Hillary,” said former White House press aide Lisa Caputo. “The discipline, the tenacity, the work ethic, a lot of that’s from him.”

Rodham never gave his children an allowance, and he didn’t dole out love to them easily. When she was in fourth grade, Clinton’s father would wake her up at dawn every single day to go over multiplication tables. But when Hillary would receive an A on a class assignment, her father would respond, “You must go to a pretty easy school.”

3. He Worked in the Textile Business

Rodham was born in Scranton, Pennsylvania, and he eventually began working in the textile industry in New York and Chicago. He would later buy a drapery company in Chicago, which sold drapes and window shades to offices, hotels, airlines, and theaters.

On the rare occasion that Clinton speaks about her father in speeches, she usually focuses on this small-business aspect of his background, saying that Rodham believed that “you had to work hard to make your way and do whatever you had to do to be successful.”

4. He Taught Hillary She Could Do Anything a Man Could

Even if he never agreed with his daughter’s politics, Hugh E. Rodham would certainly be quite proud of his daughter for becoming the first female nominee of a major party in history. In fact, he heavily emphasized during Clinton’s childhood that she could do anything a man could.

According to the Washington Post, Rodham made sure he did not force his daughter into a traditional female role, and by the time she was 10, Hillary was obsessed with baseball and was described as something of a tomboy. She played in the street with her neighbors and says she was typically the only girl on the team.

Once, when Hillary wanted to learn to hit a curve ball, her father helped for her hours on end, and Clinton later said this is “not only a true story, but a good metaphor.”

In addition to baseball, Rodham also taught his daughter how to play pinochle and how to shoot a gun.

5. He Died Shortly After Hillary Became First Lady

Sadly, Rodham was not around to see his daughter occupy the White House for very long, as he died of a stroke three months into Bill Clinton’s first term.

His death occurred a few weeks after he suffered a stroke, and The New York Times reports that Hillary Clinton was deeply shaken by this. At the time, she was having difficulty adjusting to life in the White House. After her father’s life-support machines were removed, the first lady delivered an address about the fleeting nature of life, a speech she gave entirely without a script and that she would later describe as cathartic.

“When does life start? When does life end? Who makes those decisions? How do we dare to impinge upon these areas of such delicate, difficult questions?” Clinton said at the time.

Hugh E. Rodham is buried at the Washburn Street Cemetery in Scranton, Pennsylvania. Two days after Hillary Clinton launched her 2016 presidential bid, her father’s tombstone was found toppled over, likely the result of vandalism.