Based on the information in the poem, who was Ozymandias?
All we learn of Ozymandias from the poem is that he was, according to inscription on his statue, "king of kings." His face on the statue is described as having a "sneer of cold command." HIs "mighty works" are also mentioned. However, since nothing but sand surrounds his broken statue, we can imagine that he reigned over a kingdom that disappeared a long, long time ago. Because his statue is found in the desert, we might surmise he ruled over an ancient Middle Eastern kingdom. He appears to be a narcissist who thought his great works would last forever.
Though not stated in the sonnet, we know that the poem was inspired by the statue of Egyptian pharaoh Ramesses II, who reigned from 1279-1213 BCE. The British Museum had acquired a large piece of a statue of this pharaoh. This inspired Shelley and his friend, Horace Smith, to write sonnets about it.
By using the text of the poem Ozymandius we can deduce the following about the poem's namesake. That he was an imperial ruler accustomed to dictatorial control. In his time he obviously possessed a level of power that induced a self destructive arrogance. We now call such arrogance "hubris". The wasteland that surrounds his ruined statue, his former kingdom, starkly contradicts the inscription upon his statue. The grandiose claims for his person, position, and possessions, as the "King of Kings", have a mirror image of devastation that is proportional in degree to his glory at the height of his reign. While not overtly stated, Ozymandius appears, as a universal archetype revealing the dangers of unchecked power in the ruler. As such the poem can be interpreted as a cautionary warning that is less concerned with the past failure of Ozymandius himself than with humanity's penchant for repeating his mistakes.