Anachronus should take this one, he was closer without Google. The closest I could get without it is that it was built by Germany for Russia.
This is an easy one. What was the last Armored Crusier decommissioned? *EDIT* Well maybe not that easy. I keep forgetting that I am some what obsessed with the subject of Armored Cruisers.
Not arguing for the sake of it, but... (from Wiki) "...decommissioned in 1952". Later in same article: In 1984 the Navy decided to restore her as a museum....The ship is regarded as in active service, carrying the Rear Admiral's Flag....
But I can see it both ways (damn this historical perspective). I am inclined to think that I was wrong and it should be Averoff. A victory for the Italians either way.
...And besides, Armored Cruisers will live forever in our hearts, if only 'cause they're so very, very cool