This is the 17364th most frequent Korean word.
선언했던
"Had declared."
In this sentence, '선언했던' refers to a past tense action where someone announced or declared something publicly.
그가 자신의 계획을 공개적으로 선언했던 것은 모두를 놀라게 했다.
His public announcement of his plans surprised everyone.
Here, '선언했던' is used to describe goals that were declared in the past.
우리가 당시 선언했던 목표는 현재 그대로 유지되고 있다.
The goals we declared back then are still being maintained today.
'선언했던' indicates a past declaration by a subject about a significant change.