"I know her loss will be deeply felt throughout the country, the realms and the Commonwealth, and by countless people around the world."

Tributes poured in as Buckingham Palace announced Thursday that Britain's Queen Elizabeth II has died. The 96-year-old monarch—who ascended the throne when Winston Churchill was prime minister—was a symbol of stability in an era of sweeping social and political change.

The queen's eldest son, Charles, inherits a monarchy that faces the challenge of hewing to ancient tradition while adapting to reflect modern Britain. The 73-year-old king, who will reign as Charles III, said in his first statement that the queen's death would be felt "by countless people around the world."