Starting to plan a trip to Italy and ???

With 2 weeks, and considering how many of your interests match up with what Italy has to offer, I'd suggest spending the whole 2 weeks in that country. Take time to explore and get to know a few cities.

Church history - Rome (specifically, Vatican City) is the epicenter. Rome also has early Christian catacombs, as well as the very cool and creepy Capuchin Crypt with artistically arranged human bones.

Florence has some beautiful churches which tie in with art: Giotto designed the Duomo's campanile; you can see a replica of Ghiberti's doors on the Baptistery; visit Michelangelo's Medici sculptures in San Lorenzo and check out the Laurentian Library, designed by Michelangelo, in San Lorenzo. Museums in Florence are world-class: the Uffizi and Accademia, of course; you also might like the Museo San Marco with early Renaissance frescoes painted by Fra Angelico housed in a former monastery.

For gorgeous medieval church art, go to Ravenna for a feast of mosaics: Sant'Apollinare Nuovo, San Vitale, Sant'Apollinare in Classe (the next town over from Ravenna). Spend the night in Ravenna if possible. I took a day trip there and wished I had more time!

The biggies in Italy are Venice, Florence, and Rome. If you decide to spend all your time in Italy, here's my advice: at least 4 nights in Venice (3 full days); at least 5 in Florence (4 full days) and at least 6 in Rome (5 full days). You could plan a day trip from each of these cities.

There is so much to do, to see, and to EAT in Italy, you may well regret splitting your time there with someplace else. Really! You want hiking, try the Dolomites or Cinque Terre. Church/history, you've got Rome, Florence, Ravenna, and Assisi. Great food and wine can be found all over the place but you may want to try Bologna or driving around Tuscany going to wineries and hill towns. For music there is the famous La Scala opera house in Milan, the roman amphitheater in Verona, Puccini concerts in Lucca, Vivaldi in Venice, and probably many more I'm not aware of. For beautiful natural areas try the Amalfi coast or one of the major lakes in northern Italy (Como, Garda, or Maggiore). You could spend months in Italy and never run out of things to do.

I agree with the other replies that with only two weeks and with your interests, you won't regret spending all that time in Italy. You certainly won't run out of things to see and do! And, you'll get a bit of rest by not running from place to place (as you would have to do if you added another country).

You first steps should be to get Rick Steves Italy, and to watch his many videos on the country (available free on Hulu if you're watching from the US). In addition to the places he covers in his Italy book, think of Sicily. I just got back from a 10 night trip just to Sicily, and it was rushed; two weeks there would allow you to indulge your interests properly (I haven't posted a trip report yet, but can give more specifics if you're interested).

If you love the outdoors and have never been to Switzerland you should visit. It borders with Italy, of course. The Swiss produce some of the best wine I've ever had. Unfortunately most of that wonderful Swiss wine stays in Switzerland and never makes it to the USA.

Church History - "What Martin Luther had preached in Germany (as early as 1517), Huldrych Zwingli taught in Zurich (as early as 1523), and even more radically. By 1525 the reformation was firmly established in the city of Zurich. Guillaume Farel preached the reformation starting 1526 in Aigle, Neuchâtel, Morat, Grandson, Orbe and finally Geneva (1532) where he met John Calvin in 1536."

Ever been to the magnificent Lauterbrunnen Valley? Just google it and have a look...most beautiful place I've ever seen. We always stay in the alpine village of Mürren at an elevation of 5,413 ft. What a place! Only in dreams could I ever imagine a place like this.

So if you decide to expand from Italy then I highly recommend Switzerland.

I agree with the others. Spend your entire time in Italy. If I read your post correctly, you plan 2 weeks in Italy and an unspecified time in an undetermined country? I've only been to Italy once and had 3 weeks there. We barely put a dent into the things we could see there. Even 4 weeks wouldn't have been enough. You can find all the things you are seeking in Italy.

Are you interested in the opera? I don't know if the timing works out, but I can't imagine a better place to see it than Verona.

Go to Sicily! It's absolutely fabulous! While technically it's Italy, it's got it own charm, unique food, and the history there is amazing.
There's Palermo, of course, with some WWII history, bustling and gritty. Then there's Agrigento, the Valley of the Temples.
There's a volcano (or two), see Mt. Etna. I based myself in Taormina last time and rented an apartment and had a private guide who was awesome, great English and fabulous historical knowledge. He was also funny (sometimes unintentionally!) Taormina has a beautiful ancient Greek Theatre, within touring distance to Messina, Mt. Etna, and Syracuse. That's my suggestion! PM me if you'd like the guide's info if you decide to attach Sicily to your Italy trip!

After the touring on the East side of Sicily, we stopped for two days in Cefalu for a needed relax. (About half way to Palermo where we were departing from) The views from our hotel were so jaw droppingly beautiful that we only went to town once, preferring to stay there, enjoying the view and enjoying the wonderful meals served.

Since you mention an interest in Church history, I would suggest giving Ravenna at least two full days. The anazing mosaics offer the opportunity to see, in close proximity, orthodox and Arian representations of the same biblical accounts.

Like some have said, with only 2 weeks (is this including travel time?) I would stay in Italy. Fly into Rome or Venice, see the the other places (in Italy) and fly out of the opposite city. Spend 2-3 days in Rome, Venice, Florence, side trip to Siena. You could also get a couple days in Cinque Terre, depending on what you like. I have found it better to spend 2-3 days in a city to fully get it's feel, than rush through it in a couple of hours. Just my 2 cents. Do what you like.

I agree about staying in Italy. But if you fly open jaw into Italy and out of another country, you could use one of the budget European air carriers to fly non-stop to one of many great cities--even if just for a couple of days. Barcelona? Paris? London? Budapest? Many discount airlines fly into Rome, Milan, Pisa, Venice and Florence.

Flying can be so affordable that you don't necessarily have to choose "the country next door." I would fly if you go to Greece or Spain, for example; try www.skyscanner.com to find flights within Europe. But the closest, very attractive options would be Switzerland or Slovenia. In Slovenia, a car gives you more flexibility to get around the rural areas, whereas Switzerland is extensively connected by public transportation.

I have done a independent trip combining Greece and Italy. These two countries are quite complementary given the fact that the history of Greece is so closely linked with the history of Italy.
I've also done an all Italy stay with part mainland Italy and Sicily. It is almost like being in two different countries.
The former suggestion gives you a distinct difference in language, history and people.
The latter suggestion may be less expensive because there's less transportation cost. Also, you can see amazing Greek ruins in SW Sicily (Agrigento) and SE Sicily (Siracusa). Throw in a Mt. Etna volcano walk. Drink Sicilian wine and eat fantastically flavorful Sicilian food. Can't beat that!
In either case, when I was in either country I didn't want to leave it and go to another country - believe me.

Must see:
Florence (a wealth of art, amazing Tuscan food - steak lovers rejoice here, incredibly influential historically since this was the seat of the Medici family, a stones throw from the beautiful countryside where you can hike/bike or tour by car);

Rome (archeological sites in the City, Borghese Gallery with incredible sculptures, Roman food, Appian Way just outside the city walls with Christian burial mounds and beautiful villas)