when to use ablative when translating

Latin Learning Latin
1

The sentence I am struggling to translate into English is:
Victoria magna mihi et tibi libertatem dedit

I am confused if I should translate assuming the victoria magna is ablative (there are no macrons) by saying “by a great victory he gave you and me freedom” or if I should assume victoria magna is nomitive by saying " a great victory game me and you freedom"

2

Without context it’s impossible to say, both translations are gramatically possible. But who is he in your translation “by a great victory he gave you and me freedom”? :S The natural translation without any context given is to take victoria magna as the subject.