Why did Shelley choose to write about Ozymandias instead of any other major historical figure?

Read the following lines from wordsworth's poem and answer the question. for oft, when on my couch i lie in vacant or in pensive mood, they flash upon that inward eye which is the best paraphrase of these lines? despite being able to plant my own daffodils, i prefer remembering the ones by the bay. if i feel very sad, i look inside myself for courage to face the day with my eyes open. oftentimes, i become so tired and overwhelmed that i lay down and think of daffodils. when i am feeling empty or concerned, the sight of the daffodils comes to my mind.