July 22 Jerusalem, where a Palestinian bulldozer driver on Tuesday injured 16 Israelis ahead of a visit by U.S. Democratic presidential candidate Barack Obama, lies at the heart of conflicts in the Middle East.
Here are some key facts about the city:
Situated 760 metres (2,500 feet) up in the hills between the Dead Sea and the Mediterranean, Jerusalem has been settled for 5,000 years. It became the centre of Jewish religion and nationhood. Roman rule saw the Temple destroyed in the year 70 and Jews later forced into exile.
Muslims revere it as the site of Prophet Mohammad's ascension to heaven. For Christians, it saw the crucifixion and resurrection of Jesus.
For Muslims, the walled Old City features the golden Dome of the Rock and al-Aqsa mosque, Jews pray at the Western Wall, a relic of the Temple, and there are many Christian churches.
Britain took Jerusalem from the Ottoman Turks in World War One and ruled Palestine for the following three decades.
Under a plan to partition Palestine into a Jewish and an Arab state, agreed by the United Nations in 1947, Jerusalem and its region were to be a separate entity under U.N. rule, surrounded by Palestinian territory.
However, in fighting in 1948, Jewish forces took the western suburbs of Jerusalem and land linking it to the new Israeli state. Major powers accepted a de facto divide along a fortified Green Line between Jewish West Jerusalem and Jordanian-ruled East Jerusalem, which included the Old City.
Then as now, however, no formal sovereignty over Jerusalem was recognised by the U.N. and international powers.
When Israel and the Arab states went to war again in 1967, Israel seized East Jerusalem and the West Bank from Jordan. It later annexed East Jerusalem and surrounding West Bank villages into a Jerusalem municipality that it declared the united and eternal capital of Israel. World powers do not recognise that.
Figures vary but roughly 750,000 people live in what Israel calls the Jerusalem Municipality, covering 128 sq.km (49 sq. miles). About one in three is an Arab, mostly Muslims with some Christians, and half a million are Jews. About half the Jews and almost all the Arabs live in areas ruled by Jordan till 1967.
Israel wants Jerusalem as its undivided capital. But since the Oslo preliminary peace accords of 1993, it has been in negotiations with the Palestinian leadership who want a capital for their own eventual state in Jerusalem. Possible outcomes include a Palestinian capital in eastern areas as well as some form of shared or international control over holy sites.
Palestinians complain Israel is undermining the viability of Jerusalem as their capital, notably by building Jewish settlements that effectively cut East Jerusalem off from the West Bank and by discrimination that drives Palestinians to quit the city.
Obama attracted attention in June when he told a pro-Israeli lobby group that Jerusalem must remain Israel's undivided capital -- only to amend his stance to say the issue should be negotiated by all parties.