This unnamed man was the father of Fergus Roderick MacLeod.
Little is known about him, other than the fact that he was a human who lived in Scotland during the 17th century.
Rowena has told two different stories about him. The first she claimed that he was among many men who participated in a winter solstice orgy with her. The second was that the man was rich and married and he abandoned Rowena shortly after their child was born.
As Rowena was forced to tell the truth while she wore the witchcatcher, the second story might actually be the real one. His union with Rowena was found out by the Grand Coven, likely because their son was not a witch like his mother, forcing Rowena to flee and abandon Fergus as well.
This man is also the paternal grandfather of Gavin MacLeod.