Charles has been king for a year. Reviews on his first 365 days on the British throne are mixed, to say the least.

Royal biographer Katie Nicholl said King Charles' greatest challenge remains family drama concerning Prince Harry, Meghan Markle, and Prince Andrew.

• King Charles III ascended the British throne one year ago. 
• He automatically became monarch when his mother, Queen Elizabeth II, died in September 2022.
• Some regard his first 365 days as king a success but not everyone agrees.

It's been 365 days since the death of Queen Elizabeth II marked the start of King Charles III's reign.

One year into his tenure on the British throne, public sentiment toward Charles is varied but leans towards favorable, with a recent YouGov survey that found 60% of Britons have a positive view of the sovereign. The same poll found that 59% believe he is doing a good job as king, indicating that there is still a sizable portion of the population who think otherwise. 

Mixed reviews on Charles' first year as king have been echoed by royal biographer Katie Nicholl, author of "The New Royals," and royal commentator Kristen Meinzer.

On the anniversary of Charles' first year as king, Insider spoke to both royal commentators about whether it can be considered a success and the challenges he has yet to overcome. 

Charles had 'very difficult shoes to fill,' but Nicholl says his reign has gotten off to a remarkably good start

Charles inherited the British throne from a queen whose unprecedented 70-year reign earned her a particularly beloved status among the British public.

So when it came time for Charles to step up to the plate, Nicholl said it's not surprising there were questions about whether he could replicate even a fraction of his mother's success.

"The queen was such a widely loved and respected figure," Nicholl said. Queen Elizabeth was just 25 years old when she inherited the throne and did so at a time when Britain had a "very different sociopolitical landscape," she added.

Meanwhile, Charles, the longest-serving heir apparent, "came to the throne under very different circumstances," she added. 

"There was no guarantee that Charles' first year as king was going to be the success that it has been," Nicholl said. "He was stepping into very sizable shoes and very difficult shoes to fill."

'Not rocking the boat' is Charles' greatest success, Nicholl says

According to Nicholl, Charles' first year as king can be considered a success on the basis that he's been able to keep the monarchy steady by sticking to traditions long-held by his predecessor. 

"His great success has been, firstly, not rocking the boat, keeping the traditions, the diary dates, the fixtures of the royal calendar, the events that the queen held so dear," she said. Traditions such as Christmas at Sandringham and routine visits to Balmoral "punctuate" the year of most Britons and help them identify with the royal family, Nicholl added. 

If Charles had made any major changes to those fixtures, they wouldn't have been "well received," she added. "In keeping those traditions he's continued that connection between the people and the monarchy."

There's also a familiarity with Charles among the public, which has enabled his smooth transition to the head of the monarchy, Nicholl said.

The public has known for years that Charles is an avid environmentalist, so it came as a surprise to no one that he "stayed true" to making sustainability a focal point of his reign so far, Nicholl said. 

While Charles has not yet appeared to come through on his reported plans for a slimmed-down monarchy – his inner circle still includes 10 senior working royals and key members of palace staff – Nicholl said he has already proved he is sticking to his word when it comes lessening the financial burden of the monarchy on the British public. 

"Charles came to the throne with the intention of wanting not just a slimmed down, pared-down monarchy, but a more cost-effective monarchy," she said. As an example, she cited Charles' announcement in January that he wanted to give as much as £32.5 million, or around $40.5 million, to the British taxpayer from lucrative profits made by the Crown Estate's sale of UK wind farm licenses, as iNews reported.

"It's that idea of giving something back, justifying the expense of the royal family, and scaling back where he can," she added.

But Charles failed to 'embody the best of British values and identity' in his first year as king, Meinzer says

Not everyone considers Charles' first year as king to be such a resounding success. According to Meinzer, the success of a monarch in the UK is measured by whether they can "embody the best of British values and identity" and "exude stability, as they are intended to outlast any one elected official."

"Based on both these measurements, I'd say that Charles is not succeeding as a monarch," she said. 

A glaring example, according to Meinzer, has been his inability to do what his mother never did – apologize for the monarchy's racist past.

Compared to King Wilhelm-Alexander of the Netherlands, who made headlines earlier this year for his monumental first-person apology of the Dutch monarchy's role in the historic slave trade, Charles has remained largely silent on the topic.

By doing so, Meinzer said he's "failed to present the UK as a multicultural, empathetic, and educated place that takes responsibility for its misdeeds."

"Charles has only gone so far as to passively express 'sorrow' about slavery and agreed to cooperate with research into the British monarchy's possible links with transatlantic slavery," she said, adding that the king has yet to take responsibility for those links despite "evidence that they're real."

But his greatest failure, Meinzer added, has been allowing the rift with Prince Harry and Meghan Markle to continue while simultaneously appearing to welcome Prince Andrew back into the royal fold.

"This also crosses over with the matter of stability," Meinzer said. "Just how stable is a monarch who can't even align himself with the right members of his own family?"

Looking ahead, Charles' family remains his biggest challenge

Nicholl and Meinzer present opposing viewpoints on the matter of Charles' success in his first year as king, but both indicate that his greatest challenge is and continues to be how he handles family matters.

Like Meinzer, Nicholl said Charles' decision to welcome Andrew back into the royal fold is questionable, especially when the Duke and Duchess of Sussex continue to be seen as royal outsiders. 

"I think this is the king sending a message that Andrew's never going to return to public life, but he's still his brother, and he remains a loved family member," Nicholl said.

Meanwhile, despite his return to London this week to promote the 2023 WellChild Awards, there were no indications that Harry had visited Charles. 

Ultimately, Nicholl said mending those broken relationships remains Charles' greatest challenge as king. 

"Essentially the royals are looked up to as role models," she added. "We look to them for that sense of unity and togetherness, and I think it's still a problem for Charles that at the heart of the royal family is this great fracture."