Did Blaze Bayley leave on his own or was he fired?

Ok, the ultimate question. Did Blaze Bayley leave on his own or did Iron Maidne fire him? Don't get me wrong I love that Bruce Dickinson is back, but I can't anywere if Blaze Bayley left on his own or if he was fired as Iron Maiden's lead vocalist. When he left were there bad feelings or was it a mutial agreement? Please help me with these questions. Thanks!