The Ancient and Honorable Artillery Company of Massachusetts is the oldest chartered military organization in North America and the third oldest chartered military organization in the world. Its charter was granted in March 1638 by the Great and General Court of Massachusetts Bay and signed by Governor John Winthrop as a volunteer militia company to train officers enrolled in the local militia companies across Massachusetts. With the professionalization of the US Military preceding World War I including the creation of the National Guard of the United States and the federalization of officer training, the Company's mission changed to a supportive role in preserving the historic and patriotic traditions of Boston, Massachusetts, and the Nation. Today the Company serves as Honor Guard to the Governor of Massachusetts who is also its Commander in Chief.