The area of its borough increased from . According to the law, the borough of Erkelenz is divided into nine districts with a total of 46 villages and hamlets (population as at 31 October 2009):   The coat of arms is parted horizontally. The upper part is blue, and contains the golden lion of the duchy of Guelders ("Geldern"). In the silver (white) lower part is a red medlar, also called rose of Geldern. The coat of arms shows the centuries-old connection to the duchy. The colours from the shield became the colours of the city: blue and white. There have been discoveries of Old and New Stone Age flint-knapping sites across the whole of the present area of the borough. Near Haberg House, north of Lövenich, there is a site of national renown. Near Kückhoven a wooden well was discovered in 1990 that belonged to a settlement of the Linear Pottery culture and had been built around 5,100 B.C. This makes it one of the oldest wooden structures in the world. North of the old village of Erkelenz, on the present day Mary Way ("Marienweg"), lay three cremation graves ("Brandgräber"), northwest to south of numerous fields of rubble. Roman bricks, hypocaust bricks and shards come from the marketplace south of the town hall. Here in the southwest corner and east of the chancel of the Roman Catholic parish church there are urn graves enclosed by glacial erratics of the early Frankish period from 300 to 500 A.D. On the south and southeast edge of the market, round jars were also found in the style of Badorf ceramics from Carolingian times. In 1906 a Roman Jupiter Column from the beginning of the 3rd century A.D. was discovered in Kleinbouslar. The Erkelenz chronicler Mathias Baux wrote in the 16th century that ""the bushes in the middle period were cleared and the soil turned into fertile fields, so that out of the harsh wilderness a corn-rich land and overall a breezy paradise was established."" From Mathias Baux's perspective, the middle period was the 8th century, which corresponds to the emergence of the Carolingian Empire. Under the present-day Catholic church lay Frankish and medieval graves without any grave goods as well as broken pieces of Badorf Ceramic and Roman bricks. The overwhelming theory is that the name "Erkelenz" belongs to the group of Gallo-Romance "-(i)acum" placenames.