Lagny sur Marne

Lagny-sur-Marne
Commune
The town hall of Lagny-sur-Marne
Coat of arms
Location (in red) within Paris inner and outer suburbs
Coordinates: 48°52′44″N 2°42′27″E / 48.8788°N 2.7075°E / 48.8788; 2.7075Coordinates: 48°52′44″N 2°42′27″E / 48.8788°N 2.7075°E / 48.8788; 2.7075
Country	France
Region	Île-de-France
Department	Seine-et-Marne
Arrondissement	Torcy
Canton	Lagny-sur-Marne
Intercommunality	Marne et Gondoire
Government
• Mayor (2014–2020)	Jean-Paul Michel
Area1	5.72 km2 (2.21 sq mi)
Population (2013)2	20,718
• Density	3,600/km2 (9,400/sq mi)
Time zone	CET (UTC+1)
• Summer (DST)	CEST (UTC+2)
INSEE/Postal code	77243 /77400
Elevation	37–112 m (121–367 ft) (avg. 44 m or 144 ft)
1 French Land Register data, which excludes lakes, ponds, glaciers > 1 km² (0.386 sq mi or 247 acres) and river estuaries. 2Population without double counting: residents of multiple communes (e.g., students and military personnel) only counted once.

¹ French Land Register data, which excludes lakes, ponds, glaciers > 1 km² (0.386 sq mi or 247 acres) and river estuaries.

Lagny-sur-Marne (pronounced [laɲi syʁ maʁn]; English: Lagny on the Marne) is a commune in the eastern suburbs of Paris, France. It is located in the Seine-et-Marne department in the Île-de-France 26.1 km (16.2 mi) from the center of Paris.

The commune of Lagny-sur-Marne is part of the Val de Bussy sector, one of the four sectors in the "new town" of Marne-la-Vallée.

From 644, Lagny-sur-Marne was the site of Lagny Abbey, a monastery founded that year, and after its destruction by the Normans refounded about 990. The monastery was seized by the state at the French Revolution and its buildings are used since 1842 as the offices of the municipality.

During the Middle Ages Lagny-sur-Marne was one of the most popular places for tourneys in Northern France. In November 1179 a notable tournament was held by Louis VII of France in honour of the coronation of his son.

In 1170, the young knight Baldwin of Bethune and his lifelong friend, William Marshal were at the court of Henry the Young King. In 1180 at the great international tournament of Lagny, Baldwin was a knight banneret, leading the Flemish team while William headed the English team.