Of a few, too little is known to be sure whether they were Indo-European or not.
The chief reason for grouping the Indo-European languages together is that they share a number of items of basic vocabulary, including grammatical affixes, whose shapes in the different languages can be related to one another by statable phonetic rules.
At the beginning of the Common Era, Baltic and Slavic tribes occupied a large area of eastern Europe, east of the Germanic tribes and north of the Iranians, including much of present-day Poland and the states of Belarus, Ukraine, and westernmost Russia.
The Slavic area was in all likelihood relatively small, perhaps centred in what is now southern Poland.
It presumably continues one of the very poorly attested ancient Indo-European languages of the Balkan Peninsula, but which one is not clear.
In addition to the principal branches just listed, there are several poorly documented extinct languages of which enough is known to be sure that they were Indo-European and that they did not belong in any of the groups enumerated above (e.g., Phrygian, Macedonian).
The earliest Latin inscriptions apparently date from the 6th century Kuchean).
One group of travel permits for caravans can be dated to the early 7th century, and it appears that other texts date from the same or from neighbouring centuries.
The massive similarities between Sanskrit and Latin and Greek were noted early, but the first person to make the correct inference and state it conspicuously was the British Orientalist and jurist a stronger affinity, both in the roots of verbs, and in the forms of grammar, than could possibly have been produced by accident; so strong, indeed, that no philologer could examine them all three, without believing them to have sprung from some common source, which, perhaps, no longer exists.The oldest Hittite texts date from the 17th century .Examples of modern Indo-Aryan languages are Hindi, Bengali, Sinhalese (spoken in Sri Lanka), and the many dialects of Romany, the language of the Roma.But in the 5th century Baltic-speaking area, however, contracted, and by the end of the 20th century Baltic languages were confined to Lithuania and Latvia.The earliest Slavic texts, written in a dialect called Old Church Slavonic, date from the 9th century .