The nation of Israel descended from Jacob, whose grandfather was Abraham and father was Issac. And after spending his life struggling against men and resisting God, he has a strange encounter with God, whom appeared to him in the form of a man. On the run from his pursuing brother Esau and in camp for the night, Jacob found himself alone as he wrestled with this God / man in a violent struggle until daybreak - so intense that Jacob's hip socket came out of joint. Not letting God go, even though injured, Jacob asked for His blessing. And so it is in Genesis 32 (see below) that God blesses Jacob and renames him "Israel" - the first use of this name found in the Bible (see below). And thus, the nation of Israel later sprang from the 12 sons of Jacob (per the chart above).
Jacob (later renamed Israel) was the son of Isaac and Rebekah. His name means “he grasps the heel” or “he cheats.” Jacob had used deception to receive his father's blessing intended for his brother Esau. In great fear of Esau, Jacob then fled to the home of his uncle Laban. When Jacob asked permission to marry Laban’s daughter Rachel, Laban agreed but then tricked him into marrying her older sister Leah instead. However, Jacob was later allowed to marry Rachel as well, and eventually he became the father of 12 sons and a daughter. And from those 12 sons came the 12 tribes of Israel. And descending from Jacob eventually came King David, and far later, Jesus the Messiah (from the Tribe of Judah).
God gave Jacob his new name, "Israel," in Genesis 32: 27 And he said to him, “What is your name?” And he said, “Jacob.” 28 Then he said, “Your name shall no longer be called Jacob, but Israel, for you have striven with God and with men, and have prevailed.”