Hola Gertrud

This action is indeed referring to the past but we sometimes use the present tense to refer to a past action in order to bring the action closer to the listener. This is called "el presente histórico". I believe this same technique is used in English in literature and when narrating historical events for example. 

Using the preterite is obviously correct too. 

We have a Kwiziq lesson on this. Have a look here.

I hope this clarified it.

Saludos

Inma