Vocabulary

There are Albanian words which have cognates (of non-Latin origin) in Romanian and there is a theory that the Dacian language, spoken by the Dacians before the Romanization was a language related to proto-Albanian.
The Illyrian Vocabulary is very small and is mainly of peoples names and places. A great deal of this name have a meaning in modern Albanian:
ylis - ylli - Star
Bardylis - White Star
Thetis (godess of the sea)- Deti - Sea
Emathia - e madhia - big, Great
Malion - Mali - Mountain
Dhea ( Gea equivalent) - Dheu - Ground, Earth, (Mother Earth)
Di, Diti - Dita - Day

The earliest accepted documentation in the Albanian language is from the 15th century AD, even though recently claims have been made for documents dating late 12th to have been found, one in the Vatican Library and another one in the Athos Monastry in Greece. Church documents in Latin have passages mentioning "la Lingua Albanesca" in the 12th century as well. This is a time when Albanian Principalities start to be mentioned and expand inside and outside the Byzantine Empire. It is assumed that Greek and Balkan Latin (which was the ancestor of Romanian and other Balkan Romance languages), would exert a great influence on Albanian. Examples of words borrowed from Latin: qytet < civitas (city), qiell < caelum (sky), mik < amicus (friend). But note Illyrian God of friendship was called "Mikon". The Illyrian Goddes of hunting "Zana", "Thana", or "Dhiana" to be seen in the Roman deities as "Diana" is always pictured with a goat. Note "Dhiana" meaning "Lady of the Goats" in Albanian.
After the Slavs arrived in the Balkans, another source of Albanian vocabulary were the Slavic languages, especially Bulgarian. The rise of the Ottoman Empire meant an influx of Turkish words; this also entailed the borrowing of Persian and Arabic words through Turkish. Suprisingly the Persian words seem to be absorbed the most. Some loanwords from Modern Greek also exist especially in the south of Albania. A lot of the loaned words have been resubstituted from Albanian rooted words or modern Latinized (international) words. The random use of loaned words decreases everyday and is considered as "Villagers Talk" and is made fun of.
Even though a lot of foreign influences have come and gone the proper Albanian Language has managed to survive and earn its own category in the Indo-European tree of languages. The language structure makes it an old language and whether it is the descendand of an Illyrian Dialect or not has divided the linguists today.

References

Encyclopædia Britannica, edition 15 (1985). Article: Albanian language
Huld, Martin E. Basic Albanian Etymologies. Columbus, OH: Slavica Publishers, 1984.
Martin Camaj, Albanian Grammar, Otto Harrassowitz, Wiesbaden
Orel, Vladimir. A Concise Historical Grammar of the Albanian Language: Reconstruction of Proto-Albanian. Leiden: Brill, 2000.