The Queen has been struck by the "sense of purpose" of younger generations as they fight climate change, she says in her annual Christmas message.
Her Majesty Queen Elizabeth II said newer generations face different problems to those hers did in their youth, but said they have been fought with "a similar sense of purpose".
The Queen's comments came after a year of school strikes led by Greta Thunberg, and marches across London and the rest of the world in protest of what is seen as inaction on climate change.
She also marked the many anniversaries of the year, including the moon landing and D-Day, noting her father's "look of concern" about the plans, when he "could share that burden with no one".
She said: "As a child, I never imagined that one day a man would walk on the moon. Yet this year we marked the 50th anniversary of the famous Apollo 11 mission.
"As those historic pictures were beamed back to Earth, millions of us sat transfixed to our television screens, as we watched Neil Armstrong taking a small step for man and a giant leap for mankind – and, indeed, for womankind. It's a reminder for us all that giant leaps often start with small steps."
Speaking of D-Day she said: "For the 75th anniversary of that decisive battle, in a true spirit of reconciliation, those who had formally been sworn enemies came together in friendly commemorations either side of the Channel, putting past differences behind them.
"Such reconciliation seldom happens overnight. It takes patience and time to rebuild trust, and progress often comes through small steps."
Her annual message remarked on the "bumpy" year for the royals, which included her husband Philip being involved in a car crash, as well as a short hospital trip before Christmas, and her son Andrew facing controversy over his friendship with Jeffrey Epstein.
But she also noted the arrival of her newest great grandchild, saying: "Two hundred years on from the birth of my great, great grandmother, Queen Victoria, Prince Philip and I have been delighted to welcome our eighth great grandchild into our family."
She also appeared to acknowledge the ongoing political difficulties in the country, with the divide over Brexit continuing into another year.
She said: "As Christmas dawned, church congregations around the world joined in singing It Came Upon The Midnight Clear. Like many timeless carols, it speaks not just of the coming of Jesus Christ into a divided world, many years ago, but also of the relevance, even today, of the angel's message of peace and goodwill.
"It's a timely reminder of what positive things can be achieved when people set aside past differences and come together in the spirit of friendship and reconciliation. And, as we all look forward to the start of a new decade, it's worth remembering that it is often the small steps, not the giant leaps, that bring about the most lasting change."
It is not the first time her festive message has hinted at a divided Britain. Last year, she spoke about the need to treat all people with respect even when there are "deeply held differences".