However great a man may be now, his greatness will be valueless in the future. The poem 'On the Vanity of Earthly Greatness' is about the human greatness which has been put in the shadow due to the course of time. Here in this poem the poet is trying to depict the extreme power of time which can easily wash the name, fame and greatness. The poet brings forth the examples of mastodons, the Roman Emperor Charlemagne, grizzly bear and the Great Julius Caesar to support this notion of transitoriness.
According to the poet, the tusks of mastodons used to fight powerful wars in the past are now playing objects. Similarly, the sword of the great Roman emperor who won many wars is now rusted. Likewise, everyone was afraid of the grizzly when it was alive but now its fur has been used for sitting purpose. Finally, the great Julius Caesar was the powerful general of his time but now his armless statue has been used to decorate the room of the house. The poet here tries to show the futility (vanity) of earthly greatness. The greatness which we boast so much is destroyed by the powerful time.
Thus, the poet is of the opinion that our name, fame, and greatness are noting because they will be collapsed in the course of time. The poet also satirizes the human supposition of being great and power seeking tendencies in the modern age. This poem indirectly suggests that it is useless to be proud of our present achievement because the value of our greatness vanishes in the course of time.