Britain’s Queen Elizabeth II, who reigned for 70 years, has died at the age of 96, and her eldest son, Charles, has become king. Here’s what you need to know about who is in line to succeed after him:

Charles is currently married to Camilla Parker Bowles, who will be queen consort.

Previously, he was married to and divorced from Princess Diana, who died in 1997. Prince William of Cambridge, their eldest son, is now first in line to the throne, according to the royal family’s website.

Second, third, and fourth in line to the throne are the children of Prince William and Kate Middleton, Prince George, Princess Charlotte, and Prince Louis. George is the oldest at nine years old.

Fifth in line is Prince William’s younger brother, Prince Harry, who married American actress Meghan Markle. They have “stepped back as senior members of The Royal Family,” the website says. Their two children are sixth and seventh in line.

Eighth is Prince Andrew, Prince Charles’s brother, who was entangled in scandal for his past ties to Jeffrey Epstein, the US financier who killed himself while awaiting trial on sex trafficking and conspiracy charges. Andrew is followed by his children and grandchildren.

The other two children of Queen Elizabeth and the late Prince Philip -- Anne, Princess Royal and Edward, Earl of Wessex -- and their children and grandchildren follow.

A total of 23 people are now in the line of succession.

The website notes, “The succession to the throne is regulated not only through descent, but also by Parliamentary statute.”

Parliament more than 300 years ago laid down various conditions that the sovereign must meet. The conditions include a ban on Roman Catholics succeeding to the throne and a requirement that the sovereign must be in communion with the Church of England and must swear to preserve the established Church of England and the established Church of Scotland, the website says.

Arianne Chernock, a professor of British history at Boston University, said the religious requirements “have to do quite a bit with the fact that the sovereign is the head of the church of England. It’s a religious role as well.”

Amendments have been made in recent years to the system, including ending male primogeniture, which allowed a younger son to leapfrog an elder daughter in the line of succession; ending the requirement that those who marry Roman Catholics be disqualified from the line of succession; and limiting the number of those who require the monarch’s permission to marry to the sixth closest to the throne.

The system has “evolved over centuries,” Chernock said, but “it is open to modification.”

She said that the queen’s death was an important moment “in the sense that Queen Elizabeth ... never carried political power per se, but she was a hugely central and symbolic figure in national and global culture and politics, and a very stabilizing force at that, especially with all the tumult and turmoil of recent years.”

It’s not clear how Charles will fare as king, she said. “The longevity of the institution stems from the fact that it’s an institution that stretches back centuries. It’s never just about the person inhabiting the role. Charles will have, at least, some good will behind him, but he comes to the position with a much more challenging personal history. People know far more about him. So I think it will be a more challenging reign,” she said.