LONDON (AP) — The death of Queen Elizabeth II set in motion a tightly choreographed series of ceremonial and constitutional steps, as Britain undergoes a period of national mourning and enters the reign of King Charles III.

A long-established 10-day plan, code-named Operation London Bridge, covers arrangements for the queen’s final journey to London and state funeral. Here is a look at what will happen in the coming days:

Thursday, Sept. 15

— The queen’s coffin lies in state in Westminster Hall in London for the first of four full days. Thousands of people joined a huge line to pay their respects to their late monarch. By midday, the queue had grown to 4.4 miles (7 kilometers), winding past Tower Bridge.

Friday, Sept. 16

— The king and queen consort will visit Wales, the last leg of their royal tour of the four nations that make up the United Kingdom.

— On Friday night, the king and his three siblings — Princess Anne, Prince Andrew and Prince Edward — will hold a 15-minute vigil around the queen’s coffin as it lies in state.

Sunday, Sept. 18

— Britain holds a “national moment of reflection” with 1 minute of silence at 8.p.m. (1900 GMT, 3 p.m. EDT).

Monday, Sept. 19

— The queen’s lying in state period finishes early Monday morning.

— The king will lead the royal family in a procession that takes the queen’s coffin from Westminster Hall to nearby Westminster Abbey for a state funeral that begins at 11 a.m. Leaders and dignitaries from around the world are expected to attend.

— Two minutes of silence will be observed across the U.K. at the end of the funeral.

— The funeral marks the end of 10 days of national morning, and the day will be a public holiday across the U.K.

— A committal service for the queen takes place at St. George’s Chapel in Windsor on Monday afternoon. She will be interred alongside her late husband, Prince Philip, in the chapel in a private service later that night.

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