Can you please be a little more specific about what you mean? What are you defining as "peace"? Are you referring to only Top-level nation wars or all skirmishes? What about violence that isn't nation-state level, such as The Troubles in Ireland or Terrorism? By "recent" how far back are you referring to (ie. Post-WW2?) Do you count Russia and/or Eastern Europe as part of "Europe" or are you referring to only the Western nations? Are you asking about pre-Modern eras too (where the borders/countries are completely different)? Depending on how you define it, you could get many, many, different answers that could all feasibly be correct from a certain point of view (and would break the 20 year rule in many cases).

Here are some other threads that may interest you and/or answer your question or at least point you in the right direction:

• List of conflicts in Europe

• Has there ever been a time when the world was at peace? If not, what's the closest we've gotten?

• Question about peace in Europe.

• In the light of the Nobel prize of peace: Were countries in the European continent more involved then other countries in other continents in the past 200 years?