What court should I use for making a claim for priceless property?

I was evicted from my home without my knowledge by my landlord whilst I was away due to sickness. I found that my property had been disposed of or destroyed without my permission or knowledge. Among the items was a collection of family history memorabilia going back several generations including old coins and medals and doents worth millions. Other items such as about 20 000 old photographs from the 1920s, 30s, and 40s were priceless to family members and some historians but not worth much to others. What is the procedure to make a claim? Should I use the High Court or a County Court? Is Legal Aid available?