The earliest mention of Nicosia is in the clay prism of the Assyrian king Esarhaddon in 672 BC. This is a mention to the city-state of Ledra located on the site of Nicosia, and the city is named "Lidir". The name Ledra and variations (such as Ledroi) remained in use as late as 392 AD, when it was used in writing by Saint Jerome. However, that text also refers the city as "Leucotheon", and early Christian sources of this period are the first to use similar variations of the name Lefkosia (e.g. Leuteonos). The origin of the name "Lefkosia" is considered by scholars to be a "toponymic puzzle". The name is recorded in the majority of Byzantine sources as "Leukousia", and it is accepted in literature that the name "most probably" derives from the Greek phrase "leuke ousia" ("white estate").