Bitcoin's block reward halves from 50 BTC to 25 BTC at block 210,000 on November 28, 2012. The first test of Satoshi's programmatic monetary policy -- proving the supply schedule would execute exactly as designed, with no central authority required. Bitcoin was trading around $12 at the time. Skeptics predicted miners would abandon the network, but hashrate continued to climb. Within a year, the price would surge past $1,000 -- establishing the post-halving bull cycle pattern that has repeated with every subsequent halving.
Bitcoin Wiki: Controlled supply