This does depend on where you live and how old your Grandmother would be now. You don't say whether or not your Dad was adopted.
If your dad has his birth certificate does it mention his father? Does he know his father at all.
One way of doing this is to look at the General Register Office Records to see if his mother ever married if she wasn't married at the time of his birth. You can do this either through Ancestry online or Ancestry UK or 1837 online.
You could look at old electoral registers for the area she lived in or subscribe to eroll online (UK) and search under her name. The problem is she may have married and changed her name.
I would be inclined to advise you to get a good, reputable family history researcher to help you - you'll see them advertised in Family History Magazines or search online for Family History researchers for the area you think she may have lived in .
Who brought your Father up? Can you ask them to tell you everything they know about his family?
Good Luck and I hope you find something helpful here.
If your dad has his birth certificate does it mention his father? Does he know his father at all.
One way of doing this is to look at the General Register Office Records to see if his mother ever married if she wasn't married at the time of his birth. You can do this either through Ancestry online or Ancestry UK or 1837 online.
You could look at old electoral registers for the area she lived in or subscribe to eroll online (UK) and search under her name. The problem is she may have married and changed her name.
I would be inclined to advise you to get a good, reputable family history researcher to help you - you'll see them advertised in Family History Magazines or search online for Family History researchers for the area you think she may have lived in .
Who brought your Father up? Can you ask them to tell you everything they know about his family?
Good Luck and I hope you find something helpful here.