The dative of purpose

Closely related to the above, the dative can also express the purpose or reason for an action.

go to the supermarket for my shopping.
which is an alternative way of saying:
I go to the supermarket to shop.
In Latin, an example would be:
eo ad ludum studio

The above constructions can be combined, leading to a double dative construction.

The soldiers go to the plain for a battle on behalf of Anthony.
which is an alternative way of saying:
The soldiers go to the plain to fight for Anthony.
which in Latin would be:
milites ad campum pugno Antonio eunt.

The second dative (the 'on behalf of whom' one) is also called a dative of reference.