Name
- Mason, Morgan1
- Matthew Llywelyn Goch1
- Merddin ab Taliessin1
- Meredith, Family1
- Meredydd ab Niclas1
- Middleton, Pierce1
- Middleton, Robert, of Add MS 148901
- Morgan Talai1
- Morgan ab Hywel ab Tudyr1
- Morgan, James, of Add MS 149351
- Morgan, Rowland1
- Morris, Family1
- Morris, Henry, of Add MS 148981
- Morris, Robert, of Add MS 149571
- Mortimer, Roger, of Add MS 149351
- Morys Richard1
- Morys ab Howel1
- Morys ab Llywelyn1
- Mostyn, Family1
- Nennius1