Assault occasioning grievous bodily harm (often abbreviated to GBH) is a term used in English criminal law to describe the severest forms of battery. It refers to two offences that are created by sections 18 and 20 of the Offences against the Person Act 1861. The distinction between these two sections is the requirement of specific intent for section 18; the offence under section 18 is variously referred to as "wounding with intent" or "causing grievous bodily harm with intent", whereas the offence under section 20 is variously referred to as "unlawful wounding", "malicious wounding" or "inflicting grievous bodily harm".
The offence is also known in Canada, as the most severe gradation of assault. It is a tradition handed down since at least 1879. It shows up in 10 U.S.C. § 920(g)(4), which deals with "rape and sexual assault generally".
