" Rome was not built in one day "
Meaning:
Major and important projects take time.
Example:
The new airport won't be finished for another ten years. I know Rome wasn't built in a day but that seems too long to wait.
Where did it originate?:
Britain, 16th century. From a translation of Erasmus's proverbs.
Where is it used?:
Worldwide, but less commonly than in the past.
Hear the idiom spoken: