establish (oneself, someone, or something) as (something)

To confirm oneself, someone, or something's role or reputation as being a certain thing or having a certain status. That merger established the company as the biggest on the East Coast. I think you need to establish yourself as a tough teacher early on so that the kids actually listen to you. If she can plan this major event successfully, she'll definitely establish herself as a bright star in the company.

to validate or confirm someone or something as someone or something. As soon as we establish her as a viable candidate, we will launch the publicity campaign. She established herself as an authority on rare books.