set (oneself) up as (something)

phrasal verb

set (oneself) up as (something); setting (oneself) up as (something); sets (oneself) up as (something)

1

: to try to make people believe that one is (something)

He sets himself up as a defender of the people, but he's really only interested in getting more power.

2

: to start one's own business

She set herself up as a wedding planner.