The coat of arms of Montgomery County, Maryland. It was designed and approved by the College of Arms, and was adopted as the official flag of Montgomery County, Maryland on October 5, 1976, at the request of the Montgomery County executive, under Bill 38-76 (Section 1-402 of the Montgomery County Code). 
The coat of arms uses some of the elements of the family arms of General Richard Montgomery for whom the County was named in 1776. 
Description of Coat of Arms
The broken spear at the top of the crest is probably an award to an early member of the Montgomery family.
The spear and the armor encased forearm or cubit arm are used by those Montgomery families that use the motto “Gardez Bien” or Guard Well.
The pointed yellow and black flags at the top of the crest were taken from the Maryland State coat of arms in order to reflect Montgomery County’s relation with the State of Maryland.
The gold mural crown is used by many municipalities and the indented line at its top represents the borders of a local government.
The helmet and mantling are of a style used in municipal coats of arms.
The gold fleur-de-lis in two quarters of the shield are reminders of the French ancestry of the Montgomery family.
The gold rings with blue gemstones in two quarters of the shield proclaim royal favor and protection, and are found in the family coat of arms of General Montgomery’s family.

The indented line which separates the upper quarters of the shield from the lower quarters of the shield represents the borders of a local government.
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College of Arms