HALO Trust clears landmines in war-torn countries and Prince Harry became patron of HALO Trust's 25th Anniversary Appeal in March 2013. Prince Diana visited minefields being cleared by HALO in Angola just before her death in 1997 and Prince Harry had also visited minefields being cleared by the trust before becoming a patron. He travelled to Mozambique in 2010 to see firsthand just what a devastating effect landmines can have, meeting various amputees, and even detonating several mines himself, albeit under supervision.