The world's oldest and longest-serving monarch spent the night in the hospital on Wednesday but returned to Windsor Castle the next day, with officials reporting that she was in good spirits and back to work. The queen had canceled a trip to Northern Ireland on Wednesday and was advised by medical staff to rest, although her illness was not related to COVID-19. The palace stated that she underwent preliminary investigations at the hospital on Wednesday before returning to Windsor Castle on Thursday. The reason for her medical attention was not disclosed, leading some royal correspondents to question if the official account was complete. Prime Minister Boris Johnson sent his well wishes and confirmed that the queen was back at her desk. Johnson informed reporters that Her Majesty, Queen Elizabeth, is currently back at her desk at Windsor Castle. A source close to the royal family explained that the queen had stayed at the King Edward VII hospital in London for practical reasons and that her medical team had taken a cautious approach. The source mentioned that she is now resting and performing light official duties. Queen Elizabeth, who also rules over 15 other realms, returned to work on Thursday afternoon and is carrying out some light duties. Despite significant political, social, and cultural changes that have occurred during her reign, Queen Elizabeth has remained a symbol of stability for the British people, helping to maintain the popularity of the monarchy. Despite her age, she continues to show a strong commitment to her responsibilities, earning respect from both supporters and opponents of the monarchy. Queen Elizabeth recently hosted a drinks reception for billionaire business leaders, including Bill Gates, following a green investment conference led by Prime Minister Boris Johnson. Alongside her son Prince Charles and grandson Prince William, she greeted guests like US climate envoy John Kerry without wearing masks. The Queen, who has been on the throne for nearly 70 years, is known for her good health. The most recent time she is believed to have stayed overnight in a hospital was in 2013 due to symptoms of gastroenteritis. She underwent successful surgery for an eye cataract in 2018 and a knee operation in 2003. Royal officials are reluctant to talk about her health issues. Her husband, Prince Philip, passed away in April at the age of 99, but she has continued to fulfill her official duties, although her age has led to her delegating more responsibilities to Charles and other members of the royal family. Recently, she was seen using a walking stick in public for the first time, aside from after her knee surgery. She not only mourns the loss of her husband, whom she called her source of support, but also faces challenges as her son Prince Andrew has stepped back from royal responsibilities due to his association with Jeffrey Epstein, a sex offender who died in jail in 2019. Additionally, her grandson Prince Harry and his wife Meghan have distanced themselves from the royal family by moving to Los Angeles and criticizing Buckingham Palace. Queen Elizabeth's upcoming important event is welcoming world leaders at the beginning of COP26 in Glasgow at the end of the month.