I have been researching my family tree for a while and on saturday had a major break through due to a wedding certificate being unearthed

my 4 x gr grandfather was:
Samuel Townsend
Born abt 1804
in Dublin, Ireland
Died Mar 1872
in Shropshire, Staffordshire, West Midlands, United Kingdom
I have him on the England census for 1941.
I really want to find out who his family were and where abouts he was from in Dublin etc...How would i go about this? I am new to Irish research as he is the first irish person i have come across so far in my tree.
Does the 1831 census exist?
Any help would be very much appreciated
