According to The Bible, Rehoboam succeeded his father, Solomon, as king of a great united empire, but was not a good leader. He continue his father's unwise policy of swingeing taxes and then arrogantly increased them when the Israelites complained. In a very short time, the Israelites rebelled and he lost an empire, the United Monarchy of Israel. On this view, the split occurred around 921 BCE.
However, it is reported that a majority of scholars believe that there never was a United Monarchy of Israel. They say that Israel and Judah were always separate, with their own customs and even different dialects of the Hebrew language. Arguably, the biblical authors created a United Israel in order to instil national unity and national pride, in a time of great difficulty for Judah, and they needed an explanation as to why this great empire ceased to exist. Rehoboam and his lack of proper leadership were the convenient explanation.
In about 926BC, Israel split into two kingdoms: Israel (in the north) and Judah (in the south)
After Solomon's death, Israel split into the two kingdoms of Judah and Israel. Israel now had ten tribes and Judah had two.
The south.
Israel and Judah.
Solomon's onerous taxes and his favoritism toward Judah, the southern part of the kingdom.
The two tribes, Judah and Benjamin, were collectively called Judah or Judea. See also:More about the split
You aren't; he was a king over Israel before it split into the two kingdoms of Judah and Israel
Nowadays, Israel is not divided into two kingdoms, but thousands of years ago, Israel was split into two kingdoms called "Yehuda" and "Israel". Both kingdoms were Jewish and both had their own ledership, but only one kingdom, "Yehuda", was oficially ruling the land of Israel and Jerusalem
Israel and Judah
After King Solomon's death, Israel separated into two Kingdoms - the Northern Kingdom of Israel which consisted primarily of 10 of the 12 tribes of Israel, and the Southern Kingdom of Judah which consisted primarily of tribe of Judah and Benjamin. It should be noted however, that each Kingdom had members of all 12 tribes of Israel.
The split between Israel and Judah occurred around 930 BCE after the death of King Solomon, following a succession crisis. Israel fell to the Assyrians in 722 BCE and Judah later to the Babylonians in 586 BCE.
When the state was first established, the people who established it were strictly secularists, and there was a militant "rebellion against the past." The name "Judah" is a bit too ancient sounding, too archaic. Israel is ancient too, but it is nowhere near as archaic sounding. In the actual ancient times, when the unified Kingdom of David split into the northern Kingdom of Israel, and the southern Kingdom of Judah, the northern kingdom was renamed "Israel" to rebel against the rule of the tribe of Judah. The northern Israelites, had rejected Judaism in favor of pagan worship, religious split is what caused the division.