The languages of Europe may represent the history of ancient migrations into the peninsula - and subsequent development.
Basque belongs to no known language family and may be a descendant of the oldest layer of languages. The fact that there seems to be a small overlap of vocabulary with languages in the Caucasus may show that it is the last remnant of a family of languages once covering all the space between the Atlantic and the Caucasus. But very little is settled about its origin because there is so little evidence.

In the last 4000 years there have been a series of movements of peoples into Europe, probably from the general direction of Central Asia. Most of the languages of Europe belong to the Indo-European family. In the far west are the Celts (Kelts) whose languages may descend from the first Indo-European migrants - perhaps the ones who brought agriculture. These seem to have come in two waves, with the Irish group (Goidelic) the earlier and the Welsh (Brythonic) the later. The next invasion was of the Germanic peoples. Further east are the Slavs.

There is another family, the Finno-Ugrian languages including:

Finnish, Hungarian, Sami (Lapp) (Turkish might be included as a member of the wider Ural-Altaic family - though this is not now considered valid by linguists). These derive from north Central Asia and are now represented all over the former Soviet Union, especially in Siberia;

and

The Indo-European family is represented in Europe by:

the Germanic group of languages, including:

English, Dutch, Frisian, German, Danish, Faeroese, Icelandic, Norwegian, Swedish;

the Italic group is represented by the descendants of Latin:

Catalan, Corsican, French, Italian, Ladino, Sard, Sicilian, Spanish, Portuguese, Romanian, Romansch, Vlach.

The Kelts probably arrived in Europe before the Germans and are represented by:

Irish and Scots Gaelic, Cymric (Welsh and Breton).

The Slavic group is represented by:

Russian, Byelorussian, Ukrainian, Polish, Czech, Slovak, Serbian, Slovenian, Croatian, Bulgarian, Macedonian. Wendish and Sorb may still survive in eastern Germany.

Greek and Albanian form two groups on their own. Lithuanian and Latvian form the Baltic group with some very ancient Indo-European features.

Each language has been influenced by other languages - this is because "descent" is not a simple process like that of plants and animals. All languages contain, from the very earliest texts, elements from other languages. Thus the earliest Anglo-Saxon has a few Latin words in it perhaps from the time their ancestors served as mercenaries in the Roman Empire, and even some Persian words, from the time their migrations took them past the Old Persian Empire. Modern languages show extensive adoption of words and concepts from other languages. English itself preserves the history of the peoples of Britain with words from the Welsh, Latin, French and other invaders. (see Daniel Nettle - Linguistic Diversity OUP 1999). Nowadays all European languages are heavily influenced by English.

No country is composed entirely of speakers of one language, though many governments have tried to behave as though this were true. Nowadays it is uncommon in western Europe to forbid minority peoples to use their language, but this policy is still found in Greece (Turkish, Bulgarian and Vlach); and in Turkey (Kurds). Some countries, such as Italy, are more polyglot than appears from the official language, as there are many dialects which are not mutually comprehensible.

The standardisation of languages only occurred after the invention of printing (see Burke and Ornstein). Before print there was a gradation of languages: for instance, the varieties of Germanic languages from Flanders to Denmark and eastward into what is now Germany faded into each other from village to village and fishermen from Friesland could understand fishermen from the east coast of England. France was also composed of a number of vernacular areas which gradually changed: Occitanian and Provencal-Catalan are the survivors. Radio and television have helped the process of standardisation to continue.

Official languages
The European Union at present has a policy of requiring every document to be translated into the official language of every member. These are: Danish, Dutch, English, Finnish, French, German, Italian, Portuguese, Spanish and Swedish. Some must also be translated into Gaelic, the official language of Ireland. Translation was already expensive before Polish, Hungarian, Czech, Slovak, Romanian, Bulgarian, Estonian, Lithuanian and Latvian arrived with the new members of 2005 and 2007. The expense will rise exponentially. It seems likely that cost may force the adoption of fewer official languages. In several countries English is used as an important language of university education: these include the Scandinavian countries and the Netherlands. Multi-national companies use English at the Board level. In fact a form of English is already the main language of Business.

If the linguistic minorities assert themselves there would be other languages to be considered: Catalan, Frisian, Breton, Welsh, Basque as well as many Italian dialects. In France Occitanian (the language of the Southwest) is often considered a language rather than an accent.

Common languages
Until about the end of the 17th century scholarly work and international communication used Latin. From the Renaissance Italian (Florence dialect) became important for any cultured person. From the late 17th century until the early 20th French became the main cultural and diplomatic language in the west and in Russia, with German in Central Europe. Since 1945 English has taken over these roles. English is taught as a second language in all European countries. The British, however, spend little on teaching other languages. Until 1939 German was an essential language for scientists as so much original work was done in German speaking countries.

Some commentators believe German will reassert itself in Central Europe, following probable German economic dominance in this area.

However, others suspect that English will grow more rapidly, especially as freedom of migration from the latest wave of entry has so far been confined mainly to Britain and Ireland, rather than to France and Germany. Popular culture, as shown for example in the Eurovision Song Contest, shows that English is already the main language (to the annoyance of the French).

It is reported that in multi-national companies, even those with no British or Americans on the board, English is the language spoken at Board meetings.

See this BBC page European languages.

European Union on Languages in Europe

Italian university adopts English

European Union policy

Minority languages

Daniel Nettle - Linguistic Diversity

Linguistic Diversity (Oxford Linguistics)

James Burke and Robert Ornstein - The Axemaker's Gift

How technology has affected language and many other topics