The Essential
Lagny-sur-Marne, a lively residential city, had its finest hour under the Counts of Champagne who filled it with blessings. The Abbey was built then and the town became one of the main sites for the travelling fairs. But Henri III died with no succession and the small city passed into royal ownership in 1285. While unfinished, the Church has survived and in the surrounding area there is the Chateau of Guermantes which with its Proustian sound is a fine example of Louis XIII architecture.