It’s going to be a very British summer. Along with the Olympics in London, it is the Diamond Jubilee of Queen Elizabeth II, the celebration of her 60 years of monarchy.

Kicking off the celebration at 8 tonight, BBC America has a three-part documentary “The Diamond Queen,” which probably will be repeated endlessly. Narrated by writer Andrew Marr, it looks at a hardworking royal whose real power lies in her immense dignity and human touch.

Only the second English monarch to have reigned 60 years, Elizabeth Windsor was born April 21, 1926, the first daughter of a second son who was not expected to become king. With the abdication of her uncle, Edward VIII, in 1936, Elizabeth’s father, George VI, became king, and she became the heir to the throne at age 10.

Digging deep into photo and film archives, Marr has unearthed black-and-white footage of a shy young Elizabeth as a toddler, and later of she and her sister, Margaret, playing at the Royal Lodge, Windsor. It was a privileged childhood amid a dangerous time, with the constant turmoil of lurking communism, anti-monarchy fever and, later, World War II.

On February 6, 1952, with the death of her father, she became queen at 25, handling the position with the rigid discipline installed by her parents, and a sense of duty to all the members of the British Commonwealth.

Part one of “The Diamond Queen” uses historical newsreels to show her history and then segues into a look at her daily grind — visits, receptions, talking with her many prime ministers through many decades, along with commentary from her family — Princes Harry and William and others — on how she handles it.

The second part addresses the continuity of the monarchy as well as the importance of modernization and staying current with the times. The wedding of Catherine Middleton and Prince William in 2011 was reminiscent of his great-great-grandmother, Queen Mary, in 1893 and his mother, Princess Diana, in 1981. Details might be different but the royal wedding traditions were familiar. Marr says of the queen and her husband, Prince Phillip, “when they were younger they began to invite actors, writers, scientists for regular lunches.” It’s summed up as “Tradition — with a twist.”

Part three is “the nation’s grandmother,” a personal look at the queen from her coronation in 1953 to now. Despite being in the public eye, her grandson, Prince William, says “she doesn’t care for celebrity.” A look at her televised Christmas messages, which started in 1957, also shows how fashions change over time.

Marr brings a dry tone to his narration, respectful but not referential. He doesn’t skip over the bad parts — the death of her uncle Lord Mountbatten by the Provisional IRA in 1979, and the troubles of Charles and Diana.

Overall, the queen is loved in many parts of the Commonwealth partly because of her longevity. As British actress Helen Mirren comments, “she’s the only other person who’s been a total constant in my life ever since I came to consciousness. The queen was there.”