My grandparents, Thomas Muckian and Mary Theresa McKenna, were from Co Monaghan, but I don't know precisely where. My father, their eldest child, was born in Co Durham in 1915 but I can't find any record of their marriage in England. I would guess they were married before leaving Ireland so I probably need to track them down in the Catholic Church records. Any advice on the most efficient way of doing this would be very welcome!

My fathers second name is Muckian and he was from Dundalk Co Louth, His dads name was Jack. And his wife was Mary Walsh. Any ideas how I could trace back even further?

Further than when??