This medieval German surname, recorded in several spellings including Eiler, Eilers, Eilert, Euler, Eilhart, Eilermann, Ehlerding, and Eilertsen, has a pre 7th century baptismal origin. It derives from the High German words "agil" meaning an edge, and "hard", strong, brave or hardy. This style of name made up of two or more elements, was very popular amongst the people of the "Dark Ages", that is to say the years between 410 a.d., the fall of the Roman Empire, and the advent of the great Emperor Charlemagne in the 9th century. People lived short, and often dangerous lives at this time, and so they called upon all the powers that they could imagine, to protect themselves. This included giving themselves names which related to war, religion, and personal strength, of which this is an excellent example. Early examples of the surname recordings taken from authentic German charters and registers of the period, include Friedrich Eilard of Konigsberg in the year 1635, and Diderich Eilers, the son of Johann Friederich and Ahlcke Margret (nee Schue) Eilers, at Elmloh, state of Oldenburg, Germany. The coat of arms has the blazon of white and green, charged with a bend sinister in black. In chief a black bird volant, and in base a lion rampant, in gold. The first recorded spelling of the family name is probably that of Horst Eyle, which was dated 1420, in the charters of the city of Kassel, Germany, during the reign of Emperor Sigismund of Luxembourg, who reigned from 1410 to 1437.