From what I've discovered Common is an unusual name.
Louise
The Common surname is not a common name at all, but very difficult to do a search for ! (Due to the word common being used so often)
I'm also looking up the Common tree, but my links seem to go back to the Hutton, Melrose & Bowden parts of Scotland. But not one William amongst them.
From my 1901 info of Commons in England, the ony Scottish born, that I have found, are:
John Common Born 1861 in Scotland Living in Sunderland
& Mary B Common Born 1862 in Scotland Living in Sunderland
William Common Born 1849 in Scotland Living in Heaton
& Janet Common Born 1857 in Scotland Living in Heaton
This couple had 2 children (Andrew R c1898 & Norman 1900)
James Common Born 1859 in Scotland Living in Glamorganshire
Lettie Common Born 1843 in Scotland Living in West Ham
Wm Common Born 1863 in Scotland Living in Kingston Upon Hull
Lewis Edward Common Born 1872 in Scotland Living in Sculcoates
Walter Common Born 1861 in Scotland Living in Deptford