Prince Charles of Britain officially became King Charles III on Saturday, in an accession ceremony broadcast live.

"While the new Sovereign succeeds to the throne as soon as his or her predecessor dies, they are formally proclaimed at the Accession Council," the British royal palace said in a news release.

"The ceremony, held at St. James' palace, was filmed for the first time. It began with a meeting held by the Privy Council, in which the Council officially proclaimed His Majesty as King Charles III.

"The King was present for the second part of the ceremony where he held his first Privy Council meeting."

Following the Accession Council, "the Principal Proclamation was made from the balcony overlooking Friary Court at St James's Palace," the release said.

In a personal declaration, King Charles said, "I shall strive to follow the inspiring example I have been set in upholding constitutional government and to seek the peace, harmony and prosperity of the peoples of these Islands and of the Commonwealth Realms and Territories throughout the world."

He also read and signed an oath uphold the security of the Church in Scotland.