Before World War I, Palestine was a district ruled by the Turkish Ottoman Empire.
The Ottomans were defeated by Britain and her allies in the war.
After WWI, Britain took control of Palestine, but there was much trouble between the Arabs who lived there and Jews who wanted to live there too.
Jews have long historical and religious ties to the land dating back thousands of years. They believe it was promised to them by God.
In the early part of the 20th century thousands of Jews moved to the area before it became Israel to start new lives and set up new communities.
Many were escaping Europe and Russia as they were where they were being persecuted for being Jewish. Many more moved to Israel after the Holocaust, including from Arab countries.
After World War II, Britain decided to let the United Nations decide what to do with Palestine.
The United Nations suggested dividing Palestine into two countries, one Arab and one Jewish.
The Arab leaders said no to the plan, but the Jewish leaders accepted it and declared the state of Israel. The American President gave his support to the new state.
The neighbouring Arab states declared war on the new country.
After months of intense fighting, Israel and her Arab neighbours agreed to stop the war.
Israeli forces captured what is now recognised as the state of Israel by the international community. However relations between them were still tense and more wars followed.