Macsen (WLEDIG, Roman Emperor Maximus)

Madog (AP LLYWELYN AP GRIFFRI-or Madock)

Madog (AP MAREDUDD, Prince of Powys)

Madog (AP RHYS)

Madog (FYCHAN)

Maelgwn (GWYNEDD, King of Gwynedd)

Maelog (CRWM-of Arllechwedd, Caernarfonshire)

Maenyrch (lord of Brecon)

Mainwaring (branches in North Wales)

Malephant (of Upton, Pembrokeshire)

Malpas (Sir David, Descended from Owain)

Manaw (Brenin-King of Man)

Mansel (of Oxwich and Penrice, Gower)

March (AP MEIRCHION)

Marchudd (AP CYNAN)

Maredudd (or Meredith, AP BLEDDYN AP CYNFYN)

Maredudd (or Meredith, AP MORGAN)

Marsh (of Flint)

Marshal (Earls of Pembrokeshire)

Martell (lords of Llanfaches, Montgomeryshire)

Martin (lords of Cemais, Pembrokeshire)

Martin (of Pembrokeshire, lord of Treglemes)

Mathau (AB IEUAN AP GRUFFUDD GETHIN)

Mathau (or Mathew, GOCH)

Mathew (of Llandaff, Glamorganshire)

Mathew (of Lleweni Green, Denbighshire)

Mathews (of Blodwel, Llanyblodwel, Shropshire)

Mawddwy (lords of)

Meirion (MEIRIONNYDD)

Melyn (Mellyn Magnus)

Merbury (or Marbery, Justiciar of South Wales)

Mercer (of Temby, Pembrokeshire)

Meredith (of Stansty, Denbighshire)

Merfyn (FRYCH, King of Gwynedd )

Merrick (Rhys ap Meurig, of Glamorgan)