"[2] The site of the village, or at least the locality, is associated with a battle between a Dark Ages King of the Welsh Kingdom of Gwent, Ynyr, and the incoming Saxons.

The village is also associated with the incoming Normans in Wales who built many castles in this border area of the Welsh Marches and with Dafydd Gam, a local warrior and Welsh ally of King Henry V. A Free Grammar School was founded in the village, on 10 August 1654, by James Powell, Gentleman of Cymmerau.

[6] Possibly commissioned by William fitz Osbern, the Earl of Hereford, it comprised three large earthworks with timber defences.

[8][9] Sir Henry Jackson, 2nd Baronet (1831–1881) Member of Parliament (MP) for Coventry from 1867 to 1868 and 1874–1881, and a Deputy Lieutenant of Monmouthshire lived at Llantilio Court from 1873 until his death in 1881.

His son, Sir Henry Mather-Jackson, 3rd Baronet, bought the lordship of the manor of Llantilio Crossenny and the ruins of White Castle from the 9th Duke of Beaufort in May 1902.

[12][13] Llantilio Crossenny holds an annual festival of music and drama which was co-founded in the 1960s by Welsh composer Mansel Thomas.