Why doesn't the UK have a written constitution, and does it matter?

[OfTheCross]

Essentially because the country has been too stable for too long. The governing elites of many European nations, such as France and Germany, have been forced to draw up constitutions in response to popular revolt or war.

Great Britain, by contrast, remained free of the revolutionary fervour that swept much of the Continent in the 19th century. As a result, this country's democracy has been reformed incrementally over centuries rather than in one big bang. For younger countries, including the United States and Australia, codification of their citizens' rights and political systems was an essential step towards independence. Ironically, several based their written constitutions on Britain's unwritten version.

Britain's constitution has developed in haphazard fashion, building on common law, case law, historical documents, Acts of Parliament and European legislation. It is not set out clearly in any one document. Mr Straw said yesterday: "The constitution of the United Kingdom exists in hearts and minds and habits as much as it does in law."

independent

I was today years old when I found this out. 

[PeteS in CA]

The Magna Carta, Petition of Right, and English Bill of Rights are considered foundational:

https://www.bl.uk/magna-carta/articles/magna-carta-english-translation

https://www.constitution.org/eng/petright.htm

https://constitution.org/eng/eng_bor.htm

[Fishrrman]

The Brits will, eventually, GET their "written constitution".

But when they do, the writing will be in Arabic...

[Absalom]

A perspective.
Britain doesn't have a written constitution because it's traditions supersede one.
Imperial Rome endured and prospered for 1,000 years fostering the attitudes,
instincts, sensibilities and virtues that birthed Europe; which was ruled by Monarchy
till the French Enlightenment. As such Constitutionalism was largely irrelevant.
Britain had developed and embraced strong traditional precepts from its earliest
days. Additionally it is separated from the continent by the Channel which
largely shielded it from the chaos and unrest spawned by the French revolutionaries.
In effect, Britain has no need of a written document.