The company was forced to 'declare bankruptcy'. [=to formally say in a legal document that it was bankrupt]
He 'declared' himself the winner. = He 'declared' that he was the winner. = He 'declared victory'.
His 'declared' [=publicly stated] aim/goal/intention is to improve the city's downtown area.
(..) declared war on house Tyrell. They have declared war on Dorne. We must be allies now, if we wish to survive. I offer vengeance... (..)2017 TvShow: Game of Thrones Title: Stormborn Season: 7 Episode 2
(..) you get this? Littlefinger gave it to me. Littlefinger? He's here? He has declared for House Stark. Why would he give you a dagger? - He thought I'd want it. (..)2017 TvShow: Game of Thrones Title: The Spoils of War Season: 7 Episode 4
(..) - But it doesn't matter. - Mal, goddamn it! Mal, listen to me! - Because you'll be together. Sweetheart! Look at me! Mal, no! Jesus Christ! She had herself declared sane by three different psychiatrists. It made it impossible for me to try to explain the nature of her madness. So I ran. MAN: (..)2010 Inception