According to [blockchain.info][1], the block 210000 was solved on 2012-11-28 15:24:38 GMT, and was relayed by Slush's Pool. The pool's [Stats][2] page also claims to have solved that block. [1]: http://blockchain.info/block-index/322335/000000000000048b95347e83192f69cf0366076336c639f9b7228e9ba171342e [2]: http://mining.bitcoin.cz/stats/