You've only got about a week left, so you'd better hurry!
The "Costantino, 313 d.C." ("Constantine, 313 A.D.") exhibit at Milan's Palazzo Reale in honor of the 1700th anniversary of the Edict of Milan is about to close...More......
...on the 17th of March (if the exhibit period doesn't get extended...ooooo, I just noticed the two 17s. I wonder if they did that on purpose...). This scan of the little brochure should give you enough info to get there.
If you know little about ancient Milan, the de facto capital of the western ancient Roman world from the last part of the 3rd century A.D. to 402 A.D., then this is a great place (with a few caveats...aren't there always?!) to start.
If you already know lots about ancient Milan, it's still worth going, if only to see a few interesting pieces from far flung museums that you're unlikely to frequent.
I'll reserve further comments about the exhibit until after it's over...I don't want to influence you unduly.