Prince Charles' reputation has taken a major hit, but refusing to take Harry's calls is far from the future king's first mistake

• Prince Charles' popularity dropped after Prince Harry's Oprah interview, according to a YouGov poll.
• Charles has been wrapped up in scandals throughout his life, hurting his legacy.
• If he wants to succeed as king someday, Charles needs to learn from his mistakes.

Prince Harry and Meghan Markle's tell-all interview with Oprah Winfrey hasn't been great for the monarchy.

In the interview, Markle said she was having suicidal thoughts but wasn't allowed to get help during her time as a senior member of the royal family, and Harry said his father "stopped taking" his phone calls before the couple announced their step back from royal duties.

The interview was perhaps most damaging to Prince Charles, who was already being viewed unfavorably by the public after the most recent season of Netflix's "The Crown," which featured a fictionalized version of his real-life affair with Camilla Parker Bowles while he was married to Princess Diana.

According to data from a YouGov poll, Charles' popularity dropped after the CBS interview, though public opinion on other senior members of the royal family hadn't changed. Harry and Markle's popularity also dropped after their interview, according to the same poll.

It's surprising the interview changed people's perception of Charles, as it's hardly the biggest misstep the Prince of Wales has made in his life.

Charles' relationship with Princess Diana significantly changed the way people viewed him

His relationship with Diana, however, became a lightning rod for attention, initially acting as a boost for public opinion of the monarchy. The BBC reported their wedding was the "high point" of the monarchy's popularity in the 1980s.

But as their relationship crumbled, so did the public opinion of the prince.

Rumors of jealousy and infidelity plagued their relationship, and the image of their fairy-tale marriage finally shattered after details of Charles' affair with Camilla were leaked to the Daily Mail in November 1992.

The outlet released a transcript of a sexual phone call between Charles and Camilla, confirming their romantic relationship. Charles and Diana separated just a month later.

Both the Prince of Wales and Camilla faced public fallout after the events, in part because of how popular Diana was around the world.

But Charles supported his sons through Diana's death in 1997, flying to Paris to bring her body back to England and attending her funeral by their sides. His appearance as the dutiful father was positive, setting a different tone for the prince.

Charles also insisted that Diana be honored by the country, according to ABC News, which further improved public opinion of him.

Charles' reputation recovered after Diana's death, but he was still falling short as a future king

After his scandalous marriage, the Prince of Wales appeared to take extreme care with his public actions.

For instance, Charles halted plans to announce Camilla as his partner in light of Diana's death, waiting until 1999 to be formally photographed as a couple, as Insider's Mikhaila Friel previously reported.

The prince has since largely flown under the radar, marrying Camilla in a civil ceremony in 2005 and shifting to the role of dutiful grandfather as Prince William began having children.

He also became a champion of climate change within the monarchy, further rehabilitating his image while becoming the oldest heir apparent to the throne to bear the title Prince of Wales, Insider's Mikhaila Friel previously reported.

But even amid all that positive press, Charles was still making missteps that put his public image at risk.

For instance, in 2017, the Prince of Wales and the Duchess of Cornwall received backlash after laughing during an Inuit throat-singing performance, Global News reported.

Charles also did not speak out against his brother Prince Andrew after his ties to the convicted sex offender Jeffrey Epstein came out. Likewise, Charles once supported a priest who was convicted of molesting 18 young men.

Most recently, Charles received flak when Harry said his father refused to take his calls after he brought up his plan to step back from the royal family.

Despite his efforts, scandal still seems to follow Charles wherever he goes, which doesn't bode well for a future king.

Charles hasn't been the positive figure for the monarchy that he's supposed to be

The monarchy doesn't have as much political power as it once did, though the Queen still has official duties.

But the younger members of the royal family don't have those duties, so their main role is to provide positive press to the royal family through royal tours and charity work.

Charles often takes trips to support the crown and does plenty of charity work, but it doesn't seem to outweigh the scandal that has become his legacy.

The Prince of Wales has shown time and time again that he can't be counted on to be a positive role model for the Commonwealth, making it seem unlikely he'll be able to once he eventually ascends to the throne.

Charles needs to learn from his mistakes in both his personal and professional life before he becomes king.

If he can't figure out how to avoid scandal altogether, which seems nearly impossible when it comes to the British royals, he risks leaving the monarchy open to future vulnerabilities.