This morning just before 1am Sussex police were alerted to a disturbance at a residential property in Southview road in Central Peacehaven.
A large number of police units attended the scene, along with SECAmb and the KSS Air Ambulance which landed nearby on a playing field.
A man was found with serious injuries who was transferred to Hospital.
Police arrested another man on suspicion of conspiring to cause grievous bodily harm with intent and remains in custody.
A crime scene in place whist police continue to investigate the incident.
Anyone with any information is asked to Contact lewes Police on 101 or online
Photo Credit @SussexIncidents