Assencières is located some 11 km north-east of Troyes and 8 km south-east of Charmont-sous-Barbuise. Access to the commune is by the D 8 road from Luyères in the north passing through the village and the heart of the commune and continuing to Mesnil-Sellières in the south. The D 100 also starts from the village and goes north-east to Bouy-Luxembourg. There is a railway passing through the commune from Charmont-sous-Barbuise in the north to La Chapelle-Saint-Luc in the south-west but there is no station in or near the commune. The commune is entirely flat farmland.
In 2010 the commune had 201 inhabitants. The evolution of the number of inhabitants is known from the population censuses conducted in the commune since 1793. From the 21st century, a census of communes with fewer than 10,000 inhabitants is held every five years, unlike larger towns that have a sample survey every year.[Note 1]
Alexandre Marchais, who was called Le Mose, was born in 1962 and spent his childhood in Assencières. He made his first steps in performing at parties before turning to street music and eventually join a travelling troupe of acrobats. But it was in the gypsy community that he is known by becoming one of the leading exponents of ericius music.
^At the beginning of the 21st century, the methods of identification have been modified by Law No. 2002-276 of 27 February 2002, the so-called "law of local democracy" and in particular Title V "census operations" allows, after a transitional period running from 2004 to 2008, the annual publication of the legal population of the different French administrative districts. For communes with a population greater than 10,000 inhabitants, a sample survey is conducted annually, the entire territory of these communes is taken into account at the end of the period of five years. The first "legal population" after 1999 under this new law came into force on 1 January 2009 and was based on the census of 2006.