On 11 March 1978, a PLO guerilla raid from Lebanon led to the Coastal Road Massacre. Israel responded by launching an invasion of southern Lebanon to destroy the PLO bases south of the Litani River. Most PLO fighters withdrew, but Israel was able to secure southern Lebanon until a UN force and the Lebanese army could take over. The PLO soon resumed its policy of attacks against Israel. In the next few years, the PLO infiltrated the south and kept up a sporadic shelling across the border. Israel carried out numerous retaliatory attacks by air and on the ground.
The area of modern - day Saudi Arabia formerly consisted of four distinct regions: Hejaz, Najd and parts of Eastern Arabia (Al - Ahsa) and Southern Arabia ('Asir). The Kingdom of Saudi Arabia was founded in 1932 by Ibn Saud. He united the four regions into a single state through a series of conquests beginning in 1902 with the capture of Riyadh, the ancestral home of his family, the House of Saud. Saudi Arabia has since been an absolute monarchy, effectively a hereditary dictatorship governed along Islamic lines. The ultraconservative Wahhabi religious movement within Sunni Islam has been called ``the predominant feature of Saudi culture '', with its global spread largely financed by the oil and gas trade. Saudi Arabia is sometimes called`` the Land of the Two Holy Mosques'' in reference to Al - Masjid al - Haram (in Mecca) and Al - Masjid an - Nabawi (in Medina), the two holiest places in Islam. As of 2013, the state had a total population of 28.7 million, of which 20 million were Saudi nationals and 8 million were foreigners. As of 2017, the population is 33 million. The state's official language is Arabic.
Israel (/ˈɪzreɪəl/ or /ˈɪzriːəl/; Hebrew: יִשְׂרָאֵל‎ Yisrā'el; Arabic: إِسْرَائِيل‎ Isrāʼīl), officially the State of Israel (Hebrew: מְדִינַת יִשְׂרָאֵל‎ Medīnat Yisrā'el [mediˈnat jisʁaˈʔel] ( listen); Arabic: دولة إِسْرَائِيل‎ Dawlat Isrāʼīl [dawlat ʔisraːˈʔiːl]), is a sovereign state in Western Asia. The country is situated in the Middle East at the southeastern shore of the Mediterranean Sea and the northern shore of the Gulf of Aqaba in the Red Sea. It shares land borders with Lebanon to the north, Syria in the northeast, Jordan on the east, the Palestinian territories (which are claimed by the State of Palestine and are partially controlled by Israel) comprising the West Bank and Gaza Strip to the east and west, respectively, and Egypt to the southwest. It contains geographically diverse features within its relatively small area. Israel's financial and technology center is Tel Aviv while Jerusalem is both the self-designated capital and most populous individual city under the country's governmental administration. Israeli sovereignty over Jerusalem is internationally unrecognized.[note 1]
The Kingdom of Saudi Arabia is a country situated in Southwest Asia, the largest country of Arabia, bordering the Persian Gulf and the Red Sea, north of Yemen. Its extensive coastlines on the Persian Gulf and Red Sea provide great leverage on shipping (especially crude oil) through the Persian Gulf and Suez Canal. The kingdom occupies 80% of the Arabian Peninsula. Most of the country's boundaries with the United Arab Emirates (UAE), Oman, and the Republic of Yemen (formerly two separate countries: the Yemen Arab Republic or North Yemen; and the People's Democratic Republic of Yemen or South Yemen) are undefined, so the exact size of the country remains unknown. The Saudi government estimate is at 2,217,949 square kilometres, while other reputable estimates vary between 2,149,690 and 2,240,000 sq. kilometres. Less than 1% of the total area is suitable for cultivation, and in the early 1990s, population distribution varied greatly among the towns of the eastern and western coastal areas, the densely populated interior oases, and the vast, almost empty deserts.

Question: When was the region immediately north of the region where the country that secured southern Lebanon is located and the Persian Gulf established?
Answer: 1932