From 1989 to 2003, Liberia was engaged in a civil war. In 2000, the UN accused Liberian president Charles G. Taylor of supporting the Revolutionary United Front (RUF) insurgency in neighboring Sierra Leone with weapons and training in exchange for diamonds. In 2001, the United Nations applied sanctions on the Liberian diamond trade. In August 2003, Taylor stepped down as president and, after being exiled to Nigeria, faced trial in The Hague. On July 21, 2006, he pleaded not guilty to crimes against humanity and war crimes, of which he was found guilty in April 2012. On May 30, 2012, he began a 50-year sentence in a high security prison in the United Kingdom.