A Quick Translation Attempt

[Lucus Eques]

I'm trying to translate this into Latin:

"Since that day when Marius the Great defeated the Dragon of Ravenna, its [the Dragon's] spirit has ever protected our family."

Is this correct?

Ab die ipso ubi Marius Magnus Serpentum Ravennae vicerat, eius spiritus familiam nostram semper protexit.

Are there other, perhaps better ways to say "since"? or clearer word orders?

[whiteoctave]

I would say something like

anima draconis Ravennatis, usque ab die cum Marius Magnus eum devicerit, domum nostram est tuita.

lit. the spirit of the Ravennian dragon (I thought it would be nice to use the adjective, seeing as it exists), has protected our family (I used household here, as it is perhaps the wider sense that is meant: property as well as people?) ever since the day when Marius the great completely defeated it.

~dave

[Lucus Eques]

Wow, that's great, Dave, and all the little changes you made fit better for its context as well. Gratias tibi ago!