Complex sentence: The town was named Dord-Evlar (Dörd Evlər: which means "the four houses" in Azeri Turkic) because only four families were living there, when Islam entered there during Umar age, they converted to Islam.
Split into simpler sentences: The town was named Dord-Evlar (Dörd Evlər: which means "the four houses" in Azeri Turkic) because only four families were living there. When Islam entered there during Umar age, they converted to Islam.