Where did the Magyars originate from before they migrated into the Pannonian Plain?

They are thought to have come from the Khazar Khaganate, or simply Khazaria, which was a somewhat multicultural/multi-religious empire of various semi-nomadic Turkic peoples. Specifically, they came from a part of that state called Levedia (located in the Pontic-Caspian steppe). Between their time in Levedia which they are thought to have left in the mid-800's, possibly around 850, and the conquest of the Carpathian Basin, they spent approximately a half a century in a land they called Etelköz. Etelköz was in the area between the 3 rivers: Dniester, Prut & Siret.

The conquest of the Carpathian Basin began toward the end of the 9th century (895-900) and was led by Álmos, the father of the famous King Árpád, and the patriarch of the entire family that would go on to rule Hungary for centuries. They left Levedia with 7 Magyar tribes, and were joined by 3 rebel Khazar tribes, known as Kabars. Álmos died as an old man during the journey from Etelköz to what was known during the Roman Empire as Pannonia. Therefore, his son, Árpád would become known as "the founder of the country" although his father led the Magyars out of the old country.

Very little is known about this group of people prior to Álmos and their journey away from Levedia. They were illiterate, and their first mention is in the 830's in the Annals of St. Bertin. They thought of themselves as descendants of the Huns, even at that time, but obviously, the Huns had seized to exist by the end of the 4th century, so little is known about the time period between the 5th and 8th centuries, and if there really are as strong ties to the Huns as the Magyars' legends purport.