What is Queen Elizabeth II’s Platinum Jubilee? Here’s your royal guide.

Queen Elizabeth II at Windsor Castle in April. (Dominic Lipinski/Pool/AP)

LONDON — Britain is celebrating its longest-reigning monarch, Queen Elizabeth II, in her Platinum Jubilee year.

The 96-year-old queen is being toasted across the nation with four days of events showcasing the best of British pomp and pageantry. Crowds in London will try to catch a glimpse of royal family members on the Buckingham Palace balcony, while others will attend concerts and street parties or simply enjoy the national holiday.

Here’s everything you need to know about the celebrations.