Common Assault in English Law is "using or threatening unlawful violence"
It can be sometimes made up of two separate and distinct offences.
An Assault - where the defendant intentionally or recklessly causes another to apprehend
immediate and unlawful violence
and
A Battery - where the defendant intentionally or recklessly inflicts unlawful force.
Common Assault is an offence that is triable only summarily. This means it can only be tried in the Magistrates Court. The Maximum sentence for Common Assault is six months imprisonment (although the racially or religiously aggravated form of the offence caries more).
The only real defence to Common Assault in English Law is self defence though you can consent to common assault i.e. in the course of sport. The Sentencing Council produces sentencing guidelines for Common Assault which you can find here.
The Courts always take domestic assaults very seriously as do the Crown Prosecution Service. The Crown Prosecutions Service approach to Domestic Violence is here
This article is written by Robert Cashman, a practicing criminal solicitor with a national firm of Criminal Solicitors. It does not purport to be a exact statement of English law but for guidance only and you should always get independent legal advice about your specific situation.
Robert can be contacted via https://www.policestationagent.com/