Probably built on the ruins of the Roman town Regillum, the Marcellini Castrum was one of the many castles founded around one thousand due to the need to protect against the incursions of the Saracens and the Normans. The landowner's name was Gregorio de'Marcellini and the village named after him has had a troubled life. In 1220 the monks of St. Paul Outside the Walls completely destroyed the village and the fortifications, perhaps aided by the Templars. In 1278 the estate passed to the Savelli temporarily to later return to de'Marcellini who rebuilt the castle making it a big farm. After transfers to other families, it was abandoned in 1656 because of the plague and was completely destroyed. Few traces remain today.