MeestuhDuht, I don't understand you reference to the 2nd amendment. Could you please clarify your meaning?
Denmark's constitution was originally adopted in 1849 - before that it was an absolute monarchy.
The UK dates from 1707, with the union of the crowns of England and Scotland. It has a constitution, but not one that is written down in a single document.
England has a history of legal and constitutional development (Magna Carta, Bill of Rights, Common Law) that goes back a long way, and influenced the drafters of the US Constitution.
Roma/Romani are a nomadic Indian people who ended up mostly migrating to Europe. They now mostly live in eastern Europe. Somewhere between .25-0.5 million of them were killed in the Holocast. They're the original "gypsies," which word possibly originates from people thinking they were Egyptian.
Most gypsies in the UK and Ireland are Irish travellers rather than Roma, although there's Roma groups too.
I would leave it out it doesn't help the question,at all