As the world's longest-reigning monarch, Britain's Queen Elizabeth II celebrates her 91st birthday on Friday, congratulatory messages have been pouring from all over the world, including from the UAE. Dubai's Princess Haya bint Al Hussein, wife of His Highness Sheikh Mohammed bin Rashid Al Maktoum, Vice President and Prime Minister of the UAE and Dubai Ruler, sent birthday wishes to the Queen in a touching tribute post on Instagram. The Princess posted a picture of the Queen, dressed in yellow, paying tribute to the graceful monarch for her long reign and incredible achievements. Posted nearly five hours back - at the time of filing this report - the post has garnered around 3,800 likes: