Possible Clues:

• Stole across border, beginning to invade old country
• Old country merchant investing initially in tea
• Region around Prague
• Border in the middle of a place in London
• Tea cups made initially by one European region
• Region that is not party to the convention
• Region forming the western part of the Czech Republic
• Former Slavic kingdom
• Arty area
• Historical region, now home to about 60 per cent of Czechs