Buckingham Palace confirms Queen has died

STORY: Queen Elizabeth, Britain's longest-reigning sovereign, has died.

Official confirmation came late on Thursday (September 8) from Buckingham Palace in London.

Earlier in the day the 96-year-old monarch's immediate family had rushed to be with her - soon after doctors announced they had concerns about her health.

The queen, Britain's longest-reigning sovereign, had been suffering from what royal officials called "episodic mobility problems" since the end of last year.

Her eldest son and heir Charles and his wife Camilla quickly traveled to her Scottish home, Balmoral Castle, where she was staying, as did Charles' older son, Prince William.

The queen's other children Ann, Andrew and Edward - along with Charles' younger son Prince Harry - were soon en route.

Such a family gathering, outside of holiday events, was a grave indication of what was to come.

After her last health scare in October, and a night in the hospital, the queen cut back on public engagements, relocating to Windsor Castle and then Balmoral, rather than staying at Buckingham Palace.

On Wednesday she canceled a virtual meeting with senior ministers after being advised to rest by her doctors.

The previous day she was pictured appointing Liz Truss as the country's new prime minister.

Elizabeth has been queen of Britain, and more than a dozen other countries as part of a drastically reshaping empire, since 1952.

This year was her 70th on the throne - with four days of national celebrations in June.

The crowds gathered at Buckingham Palace on Thursday were there to remember their late queen.

Days of national mourning will follow ahead of a state funeral.