Parents who force their children to marry in England and Wales could be jailed for a maximum penalty of 7 years under the new laws.
From today, forcing someone into marriage will carry a maximum seven-year jail term under the 2014 Anti-Social Behaviour, Crime and Policing Act.
It is now a criminal offence to use violence, threats or any other form of coercion for the purpose of causing another person to enter into a forced marriage.
The legislation followed a consultation published in December 2011 which sought views on how the new offence should be framed.
A forced marriage is described as one in which one or both spouses do not consent to the marriage but are coerced into it by physical, psychological, financial, sexual or emotional pressure. This is different from arranged marriages where the parents may have arranged the marriage but both parties have consented to the union but can still refuse to marry if they choose to.
As the new law came into effect, the Home Secretary, Theresa May, said that forced marriage is "a tragedy for each and every victim". She added that forced marriage is an "appalling practice" and that criminalising it would send "a strong message that it will not be tolerated". It is already illegal in Scotland.