Queen Elizabeth Turns 90

Queen Elizabeth, Britain’s longest-serving monarch, celebrates her 90th birthday Thursday. Her Royal Highness will spend the day around Windsor Castle, But, she’ll give well-wishers the chance to wish her many happy returns as she unveils a plaque on the Queen’s Walkway, which opened last year.

She’ll then go on a “walkabout” with the Duke of Edinburgh to meet members of the public. The celebration will continue Friday. ABC’s Tom Rivers has more on the Queen’s birthday agenda.