Commonwealth Day, held on the second Monday in March, is a regular feature on the Queen's calendar. Each year, she attends a service of observance at Westminster Abbey, which is typically followed by a reception. (Of course, there are years where there has been an exception.) For the service, the Queen has worn a wide selection of her regular brooches in the past few years, all accompanied by her uniform of Queen Mary's Button Earrings and her Three Strand Pearl Necklace.
2013: The Queen was not in attendance at the service, due to illness. She attended the evening reception.
2006: Queen Victoria's Bow Brooch. This Commonwealth Day was celebrated in Australia, where a service was held in Sydney.
Which year is your favorite?
Photos: Getty Images/Commonwealth Flag Project/Reuters/AFP/Corbis