A phosphor represented by Formula 1: (A1−(a+b)EuaLnb)1−x(B1−cMnc)2Al(6+b−2x)Si(9−b+2x)O30  Formula 1 wherein A includes at least one element selected from the group consisting of Ca, Sr and Ba, Ln includes at least one metal selected from the group consisting of a trivalent rare earth metal, B includes at least one element selected from the group consisting of Mg, Zn, Ge and Co, a is greater than 0 and equal to or less than about 0.5, b is greater than 0 and equal to or less than about 0.25, c is greater than 0 and less than about 0.8, and x is 0 to about 0.2. Also a white light emitting device including the phosphor.