Celebrating History and Legacy:
* 70 Years of Service. 70 Years of Strength. 70 Years of Queen Elizabeth.
* A Legacy of Love, Duty, and Dedication. 70 Years of the Queen.
* From Coronation to Jubilee: A Reign of Hope and Inspiration.
* Queen Elizabeth II: 70 Years of Unwavering Devotion.
Focusing on the Future:
* Celebrating the Past, Embracing the Future. 70 Years of Queen Elizabeth II.
* A Nation United. A Monarch Beloved. A Future Bright.
* Honoring the Past, Shaping the Future. The Queen's Platinum Jubilee.
* 70 Years of Service. A Beacon of Hope for Generations to Come.
Playful and Engaging:
* Let's Party! 70 Years of Queen Elizabeth.
* The Queen's Jubilee: A Celebration for Everyone.
* Get Ready to Celebrate! It's the Platinum Jubilee.
* 70 Years of Memories, 70 Years of Joy.
Formal and Traditional:
* Platinum Jubilee: In Honour of Queen Elizabeth II.
* A Royal Celebration: 70 Years of Service.
* Celebrating 70 Years of Majesty and Grace.
* The Queen's Platinum Jubilee: A National Tribute.
Ultimately, the best slogan will depend on the specific tone and message you want to convey for your event or communication.