Hi Mick
Now this is interesting.
I half had the idea that William might be the younger brother of Michael. On his marriage certificate of 1864, William's father is given as "Thomas Brannan, gardener, dec'd". So far so good. But as explained in my first email below, when I actually looked at the St Patrick's Parish Records his father is given as "William Brannan". So I have a problem here. I would like to believe the certificate but the actual records take precedence!
I really should talk to the GRO about this.
Regards
Patrick