Prince Harry and wife Meghan Markle have confirmed they are using their children’s new royal titles, gained on the death of the late Queen Elizabeth.

Under royal rules, Archie and Lilibet were eligible to become a prince and princess as grandchildren of the monarch, Harry’s father the King.

The Duke and Duchess of Sussex used one of the titles publicly for the first time on Thursday (AEDT), when confirming the recent christening of their 21-month-old daughter, which was no royal affair.

Lilibet Diana, who was born in June 2021, was baptised at an intimate ceremony at the couple’s home in Montecito, California, on Friday.

“I can confirm that Princess Lilibet Diana was christened on Friday, March 3, by the Archbishop of Los Angeles, the Reverend John Taylor,” their spokesperson told People on Thursday.

Rev Taylor (whose title is accurately Bishop of Los Angeles) confirmed the ceremony in his “bishop’s blog”.

“At the invitation of the Duke and Duchess of Sussex, I had the blessing of presiding as the sacrament of Holy Baptism was conferred on their daughter, Princess Lilibet Diana, on Friday, March 3, at their home in Montecito,” he wrote.

“Prince Harry and Meghan were gracious hosts to the congregation of family and friends who were present.”

A source told the outlet the couple had extended an invitation to the ceremony to the King, Queen Consort and the Prince and Princess of Wales. All were no-shows.

People reports that 20-30 guests attended the ceremony, which was followed by food and dancing – “with Archie enjoying a dance with his little sister”.

Other guests included Meghan’s mother Doria Ragland and Lilibet’s godfather, actor and filmmaker Tyler Perry. He was seen arriving earlier with a 10-person gospel choir that reportedly sang Oh Happy Day and This Little Light of Mine.

The interest in Harry’s children’s titles comes after his relationship with his father hit rock bottom following the release of the prince’s tell-all memoir earlier this year. Harry made damning accusations against the royal family in Spare, including describing his stepmother, the Queen Consort, as “dangerous”, and revealing a physical altercation over Meghan with his brother, Prince William.

Thursday’s statement is the first time the Sussexes, who stepped back from royal duties in March 2020 and live in California, have publicly confirmed they want their children to be known as prince and princess.

Hours after Harry and Meghan’s statement, Buckingham Palace said it would update the royal website to reflect Archie and Lilibet’s titles in “due course”.

Sixth and seventh in line to the throne, they are officially listed as Master Archie Mountbatten-Windsor and Miss Lilibet Mountbatten-Windsor.

Lilibet on her first birthday in June 2022, at Frogmore Cottage. Photo: Supplied

Meghan said in her sit-down interview with Oprah Winfrey two years ago that the royal family refused to make her son Archie a prince and had conversations while she was pregnant about how dark his skin might be.

However, the Sussex children were not entitled to the prince and princess titles at the time they were born, as their grandfather was not yet king.

Under a precedent created by letters patent issued by George V in 1917, the title of prince or princess is conferred only on male line grandchildren of the sovereign.

Lilibet’s baptism was held less than two months after Harry and Meghan were asked to vacate their official British residence, Frogmore Cottage. That decision – made by the King – is a sign of the latest strain in relations between the couple and the wider royal family.

It is not known whether Harry will attend his father’s coronation in May. A spokesperson for the couple confirmed earlier this week that they had been invited, but said “an immediate decision on whether the duke and duchess will attend will not be disclosed by us at this time”.