William G. Dever sees this "Israel" in the central highlands as a cultural and probably political entity, more an ethnic group rather than an organized state. Ancestors of the Israelites may have included Semites native to Canaan and the Sea Peoples. McNutt says, "It is probably safe to assume that sometime during Iron Age I a population began to identify itself as 'Israelite'", differentiating itself from the Canaanites through such markers as the prohibition of intermarriage, an emphasis on family history and genealogy, and religion. The archeological evidence indicates a society of village-like centres, but with more limited resources and a small population. Villages had populations of up to 300 or 400, which lived by farming and herding, and were largely self-sufficient; economic interchange was prevalent. Writing was known and available for recording, even in small sites. The first use of grapheme-based writing originated in the area, probably among Canaanite peoples resident in Egypt. This evolved into the Phoenician alphabet from which all modern alphabetical writing systems are descended. The Paleo-Hebrew alphabet was one of the first to develop and evidence of its use exists from about 1000 BCE (see the Gezer calendar), the language spoken was probably Biblical Hebrew. Monotheism, the belief in a single all-powerful law-giving God is thought to have evolved among the Hebrew speakers gradually, over the next few centuries, from a number of separate cults, leading to the first versions of the religion now known as Judaism. The Hebrew Bible describes constant warfare between the Israelites and the Philistines whose capital was Gaza. The Phillistines were Greek refugee-settlers who inhabited the southern Levantine coast. The Bible states that King David founded a dynasty of kings and that his son Solomon built a temple. Both David and Solomon are widely referenced in Jewish, Christian and Islamic texts. Standard Biblical chronology suggests that around 930 BCE, following the death of Solomon, the kingdom split into a southern Kingdom of Judah and a northern Kingdom of Israel. The Bible's Books of Kings state that soon after the split Pharoh "Shishaq" invaded the country plundering Jerusalem. An inscription over a gate at Karnak in Egypt recounts such an invasion by Pharoh Sheshonq I. The archeological evidence for this period is extremely sparse, leading some scholars to suggest that this section of the Hebrew Bible, which includes texts written two centuries later, exaggerates the importance of David and Solomon. The earliest references to the "House of David" have been found in two inscriptions, on the Tel Dan Stele and the Mesha Stele; the latter is a Moabite stele, now in the Louvre, which describes an 840 BCE invasion of Moab by Omri, king of Israel.