Whom Should We Thank For The Existence Of Modern Britain?

There's a show on BBC  Knowledge that suggests that it was exploration and innovation that made "Britain" what it is today.  Oh, really?

The exploration did lead to the Empire, and the innovation did lead to the Industrial Revolution, but a couple of things had to happen beforehand to enable the exploration and innovation bits.  Most notably the wonderfully useful English language.  Taking it further begs the question:  where did the language come from?  Almost none of it came from the inhabitants of the British Isles themselves.  It came from outside.  The language, and any subsequent successes by the nation state of England (or, Great Britain), were the direct result of repeated, long-term conquests and occupations.

First came the Celts.  The Romans were there for several hundred years, bringing with them the beginnings of modern English.  The Angles and the Saxons brought their already Latin influenced German, and they stayed, taking "English" to a very German stage of development.  The (Norman) French came to stay in 1066,  and between that time and Shakespeare's time modern English was born, developed and perfected.  I'm not qualified to speak about the linguistic contributions of the Celts, or the less occupation minded Vikings for that matter, but without the building blocks of Latin, German and French, there would be no English language as we know it.

The English are a very interesting people, and not without their successes.  I find them to be a first class movie-making people, and very literary in general (often too literary for my taste, but that's just me).  In a just world, they should have a big holiday, like a four day weekend or something, to celebrate the various streams that came together to form the English language.  Costumes of the conquerors should be worn, and great thanks should be given for all of their bloody efforts.  And a moment of silence for all of the people that had to die so that the English language could live.  Haven't the English sufficiently lost their pride by now to allow for a holiday like this?  You'd think that they should have.