The royal siblings, great grandchildren of the Queen, were among 2,000 guests at her state funeral, joining their parents and extended family, as well as world leaders and national figures from UK.
George, nine, and Princess Charlotte, seven, walked behind the Queen’s coffin as part of a solemn procession past hundreds of guests.
As the young royals followed their great grandmother’s coffin, flanked by their parents, the Prince and Princess of Wales, Charlotte held her hands clasped in front of her while George had his arms by his side.
The young royals had arrived earlier in a car with Camilla and their mother, Kate.
George was dressed in a dark navy suit and tie, while Charlotte wore a black coat dress with pleats at the back, black tights and a hat with a ribbon tied at the back.
Ahead of the service, the Princess of Wales could be seen holding Charlotte’s hand, and giving her a reassuring touch on the shoulder.
Kate and the two children waited to one side of the abbey’s doors, watching quietly as the Queen’s coffin was borne in.
The trio then joined the Prince of Wales to form a row of four as they followed the coffin to the front of the abbey.
After taking their seats, the children could be seen studying their order of service at various points.
Charlotte could be seen looking around from under the brim of her hat while the mourners sang The Lord’s My Shepherd.
And her brother George was seen singing The Day Thou Gavest, Lord, Is Ended as he stood between his parents.
At one point, the futre King appeared to wipe a tear as the emotional day took it’s toll.
Kate could be seen comforting her son with a hand on his knee.
At the end of the service, George followed closely behind his father, while Kate put a guiding hand on the back of her daughter, as the foursome got up from their seats and stood behind the coffin.
Both children looked down at times as they filed slowly out of the abbey.
The second and third in line to the throne are also expected to be at the committal service in St George’s Chapel, Windsor Castle, afterwards.
The prince and princess’ four-year-old brother, Prince Louis, was not present.