It was designated the home of the treasury of the Delian League in 480 b.c. , an act which encouraged its growth as a center for banking and commerce.
The Delian League designated this place as the home of the treasury.  
mnli hypothesis: The Delian League designated this place as the home of the treasury.   premise: It was designated the home of the treasury of the Delian League in 480 b.c. , an act which encouraged its growth as a center for banking and commerce.