Arranged marriages were quite common in medieval ages...especially for european nobility or royalty to preserve the line, or strengthen an alliance, or as a symbol of a truce between 2 warring factions.

In the Asian setting, depending on what particular country, the reasons range from:

-payment of a debt
-preserving the family's wealth
-to forward political influence, etc.

These days, pseudo-arranged marriages don't quite work as society has evolved a lot, along with personal preferences.