Prince William, second-in-line to the British throne, arrived today for the opening of the 21st World Scout Jamboree in Hylands Park, Essex, England. The prince’s royal helicopter landed in the center of the 800-acre jamboree site about two hours before the opening arena show Saturday afternoon. Prince William and his uncle, the Duke of Kent, president of the United Kingdom Scout Association, did a brief “walk about” visiting some of the 40,000 Scouts and Scouters from the 158 countries that are attending this centennial anniversary of world Scouting’s birth.

A patchwork quilt of blue, gray, red, green, and khaki Scout uniforms filled the arena for the opening ceremonies. A roll call of nations and colorful parade of flags representing all 158 countries showed how widespread the world Scouting movement has become. (Both Afghanistan and Iraq are among the countries attending the jamboree.) As each country was announced, its contingent stood and cheered. At 3,300 youth and adults, the BSA contingent is second in size only to the U.K. It’s the largest BSA contingent to attend a World Jamboree in more than two decades.

The Duke of Kent welcomed the jamboree Scouts to the United Kingdom and read a message of greetings from Her Majesty, Queen Elizabeth II.

Saturday night, many Scouts returned to the arena for a three-hour party of rock and roll and dancing. The three-member Bel’s Boys, a teenage band from Northern Ireland with their own TV show on the British network ITV, was a great hit as they whipped the crowd into a hand-clapping, jumping frenzy. Even a light rain toward the end of the show, which also included break dancers and traditional and rock dancing from India, couldn’t dampen the crowd’s spirits.

Scott Daniels is the managing editor Scouting magazine. He is submitting a daily blog post from the 21st World Scout Jamboree, Hylands Park, Essex, England.