The name comes from l'Annoy (or l'Annoit, from Latin alnetum), which means 'the alderwood' in Picard French of Flanders.

The first small castle in Leeuwergem was built by Valentin de Lannoy in the 17th century.

[2] The branch of the Counts of la Motterie was known to have multiple men in military service of the Crown.

Jacques de Lannoy, Lord of la Motterie, died 1587:Married to Susanne of Noyelles.

Jean I de Lannoy The current main branch of the family resides in Anvaign and descends from Jacques-Adrien-François de Lannoy (1769–1835) who was married to Louise-Marie-Caroline d'Ursel, older sister of the 4th Duke d'Ursel.