Ternary hexagonal Ae₅Tt₃Z phases have been obtained from high-temperature reactions (1000−1300 °C in Ta) only for Ae (alkaline-earth metal) = Ca, Tt (tetrel) = Pb, and Z = V, Cr, Mn, Fe, Co, Ni, Zn, Ru, or Cd. The hexagonal crystal structures (stuffed Mn₅Si₃-type, P6₃/mcm, Z = 2) were refined for Z = Mn and Fe (a = 9.3580(3), 9.3554(5) Å, c = 7.009(1), 7.009(1) Å, respectively). In contrast, Ca₅Pb₃Z for Z = Cu or Ag form only with a trigonal structure (P3̄c1, Z = 2, a = 9.4130(3) Å, c = 7.052(1) Å for Cu) in which regular displacements of only the linear strings of Ca1 atoms occur. The existence of these compounds stands in contrast to the nonexistence of all binary Ae₅Tt₃ products from Ca to Ba (Ae) and Si to Pb (Tt) with a Mn₅Si₃-type structure. Therefore, it once seemed attractive to consider the Z elements in these Ca₅Pb₃Z compounds as reducing agents (electron donors). The Mn and Fe structures appropriately exhibit greatly enlarged antiprismatic calcium cavities about Z. Other indications of relatively electron-poor environments around Fe are found in its properties, which include soft ferromagnetism with an elevated magnetic moment (6.3 μ_B) and a large Fe 3p_3/2 binding energy relative to that in La₅Ge₃Fe, La₁₅Ge₉Fe, etc. The Ca₅Pb₃Mn phase exhibits metallic behavior (ρ₂₉₅ = 135 μΩ cm) and temperature-independent Pauli paramagnetism. These properties are supported by ab initio band structure calculations for Ca₅Pb₃Mn, which show strong Ca−Pb bonding and a broad Pb-based band, with appreciable Ca−Mn and Ca−Pb bonding states at and above E_F. Distortion of the Cu analogue gives strengthened Ca−Pb bonding and reduced Cu−Ca1 repulsions. A Zintl phase description of these compounds and some releated compounds in terms of closed Pb bands is not appropriate.