Who is the composer of “Jerusalem”?

There is a song in the AP Theory workbook called “Jerusalem”. It is a piano piece and is written by someone foreign, perhaps German. However, I do not know the name of him, I don’t have my book with me and would like to know. I think his name starts with a G. I’m pretty sure it is classical or romantic.

http://en.wikipedia.org/wiki/And_did_those_feet_in_ancient_time

Blake was British – so was Parry. No German connection.

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