Romania, surprisingly for many, has an Islamic history that stretches all the way back nearly 700 years.

 It is believed that the earliest Muslims arrived in the 11th century when the Pechenegs ruled in Wallachia and Moldovia. This led to the small establishment of communities mainly around teh Dobruja region on the Black Sea coast.

Later the presence of Tartars and most notably the Ottomans made the Muslim community far more visible with the Ottomans building several mosques as they expanded their kingdom.

The most famous period of the Ottoman influence involves the notorious Dracul family around whom several intriguing legends linked to the Ottiomans arise, including the apparent conversion to Islam of Radu Dracul, brother of Vlad the Impaler, and his subsequent defection to the Ottoman ranks alongside whom he fought his notorious sibling.

For a more detailed and thorough appreciation of Islam in Romania, read the wikipedia page 

If you fancy exploring the country's Islamic remnants, this article by a muslim travel writer points to some interesting possibilities