Opus 67 had a long gestation. The first phrases were pencilled in 1804 and it was presented in 1808, when Beethoven was 38. His "middle period" is also sometimes known as his "heroic" period, because of the dramatic nature of many of the compositions.
|original score from Wikimedia Commons|
Beethoven didn't come up with the name 'Emperor's Concerto'. In fact, he detested the nobility because the Imperial Theatre ignored his petition to become its permanent composer in 1807. Not only did they reject his proposal, they didn't even write back to acknowledge receipt. Who knows, maybe the insult spurred him to complete this masterpiece.
Beethoven's hearing loss began in his early twenties, and by the time he wrote this concerto it was pronounced, but he was still able to hear. Seventeen years later he would perform his Ninth Symphony (Opus 125), with his back was to the audience, and not be able to hear their applause.