Ioan Gruffudd Welsh ˈjɔan ˈɡrɪfɪð born 6 October 1973 is a Welsh actor He first came to public attention as Fifth Officer Harold Lowe in Titanic 1997 and then for his portrayal of Horatio Hornblower in the Hornblower series of television films 19982003 Subsequent roles have included Lancelot in King Arthur 2004 Reed Richards Mister Fantastic in Fantastic Four 2005 and its 2007 sequel William Wilberforce in Amazing Grace 2006 and Tony Blair in W 2008 His other film credits include 102 Dalmatians 2000 Black Hawk Down 2001 The Gathering 2003 Fireflies in the Garden 2008 The Secret of Moonacre 2008 Sanctum Horrible Bosses Foster all 2011 The Adventurer The Curse of the Midas Box 2014 and San Andreas 2015 On television Gruffudd has starred in the CW series Ringer 20112012 the ABC drama Forever 20142015 the Lifetime series UnReal 2016 SundanceITVs Liar 20172020 and the Australian series Harrow 2018present