I know that by the end of the Bronze Age the Hittite kingdom was destroyed, and that its destruction is credited to the "Sea Peoples," but between the end of the Bronze Age and the rise/dominance of Persia I don't really know anything about the history of that region.
Was there a successor to the Hittites - did someone conquer and set themselves up in Hattusa, or did that region just fall into obscurity and nothingness? I know of Assyria becoming strong after 1000BC and being one of (the?) opponent to the rising Persian empire, but other than that I know nothing. If anyone could shine a light on this dark age of history for me, I'd really appreciate it. Thanks!
Well, the Hittite Empire was quite large and there were a lot of "successor states" in the sense of states that occupied the Hittite state's former territory. In Syria (and southeastern Anatolia), a lot of Aramean and Luwian* principalities emerged in the aftermath of the Hittite state's collapse. Especially notable successor states included the Aramean Sam'al(Zincirli) and Guzana(Tel Halaf) and the Luwian Carchemish, where a cadet branch of the Hittite royal family continued to rule for several generations after the fall of Hattusa before seemingly being ousted by a coup. Further into Anatolia, the kingdom of Melid(centered on modern-day Malatya and mostly in southwestern Turkey) arose after Carchemish lost control of the area, and the kingdom of Tabal more or less in central southern Anatolia. Many of these city-states maintained active and regular trade relations with each other and with the Assyrians up to their absorption by Assyria. So there wasn't really a successor state to the Hittites but the region didn't exactly "fall into obscurity and nothingness" either. There was also more continuity with the Hittite imperial period than commonly thought as well; a number of gods popular in the late Hittite empire remained the focus of cults, some aspects of Hittite iconography remained in use in places, and of course the Luwian script used by many of these city-states and principalities originated in the Hittite empire.
*Note that "Aramean" and "Luwian" refers to the presumed ethnicity of the royal house(es) of the cities or principalities; most of these territories were quite mixed ethnically and these identities were probably fairly fluid. Briefly, "Aramean" refers to a range of Semitic speaking pastoralists some of whom urbanized in this period and came to define themselves as "Aramean" and "Luwian" refers to a range of speakers or at least users of an Indo-European language related to Hittite and written in a distinctive hieroglyphic script.
This is one of the periods of history that is accurately called a Dark Age. Because very little is known about it. There was a collapse of most of the big civilisations in the Near East (excluding Egypt) for unknown reasons. Often attributed to Sea Peoples based on certain written sources, but now doubted by historians as an explanation. Other theories are internal collapse and large scale revolts or also disease, earthquakes and other catastrophes.
It's been quite a while since I was reading about this subject, and it was never the focus of my studies, but it is extremely interesting. I can recommend Crash Course World History's episode on the subject, the information presented is good:
The Wikipedia article looks to be somewhat spotty, but might be worth your time to skim: http://en.wikipedia.org/wiki/Late_Bronze_Age_collapse