The Maryland State flag is a mixture of 2 sets of coats of arms. Each set is from one of the founding fathers of the colony of Maryland, George Calvert and Lord Baltimore. The flag was officially adopted in 1904 and is the only US state flag to be directly based on English heraldry. Maryland is the only state to have specifications for how the flag should be displayed and on which types of flagpoles it may be flown. According to the guidelines, flagpoles used to display the Maryland flag should have a gold cross bottony on top.