The poem is about powerful people and describes how their power is only temporary. The poet meets a traveler from ancient land. The traveler describes the two large stone legs of a statue.
The broken face of the statue had a frown look. Below the statue, it was written, 'I am Ozymandias, the king of kings'.
The speaker explains that time not only destroyed the statue but it destroyed the entire kingdom. The ironic meaning is, 'one despairs not at Ozymandias’s power, but at how powerless time and decay make everyone.'