Travel from London to Rome and back to London

I guess it could depend on the costs of flights. Are you going thru London because of awards flights? Why not fly directly to Rome? Can you just get a connecting flight with the airline you are flying over with? (that way if their are issues with late originating flights, they will get you on the next available flight instead of losing any money you paid for a different ticket)

...but...our very first trip over to Europe we did the same thing. We arrived at Heathrow in the morning (mid-morning) and had booked an early afternoon flight to Rome via LHR. (Now, we flew home from London because after doing Italy, we went to visit my sister who lives in the UK before coming home). I think most would tell you to just connect thru Heathrow. If you don't give yourself a big enough window to get to Gatwick and your flight over is delayed, you could be out the money for the 2nd flight. Or you could run into issues with traffic or train delays between the two. I wouldn't want to go thru the time, hassle and cost of going between airports. And we found a fairly cheap flight at the time with Alitalia (this was 2008, so prices are fuzzy, but they were under $100). We use British Airways generally for flights within Europe and mostly the flights are between $70-100.

Thank you for the very helpful info. I have booked my 21 year old granddaughter and me on Alitalia out of LHR to Rome & back. Very excited and a little nervous for our adventure of a lifetime.