The beginning of the modern history of the state of Saudi Arabia is argueably when an Islamic reformer named Muhammad ibn Abd al Wahhab and a local ruler named Muhammad bin Saud founded the Emirate of Diriyah in the year 1744. It was founded in the area of Nejd, the central part of the Arabian Peninsula. The Sa'udi emirate's leadership can be viewed as a traditional form of rule within communities of Arabia in the 18th century. Over the next century and a half the family went through a lot of opposition and hurdles. The family faced opposition from powerful families of Arabia but also rulers of Egypt and the Ottoman Empire.
In 1902 Abdul Aziz Ibn Saud, also known as Abdul Aziz Al-Saud, took over the city of Riyadh from another family named Al-Rashid. He continued to win more areas, and on 8 January 1926, he became the King of Hejaz and the Sultan of Nejd. On 20 May in 1927, the government of the United Kingdom accepted him as the King of those areas ruled by him (the Nejd and Hejaz). His kingdom now became a sovereignty. The modern nation state of Saudi Arabia was established in 1932 as 'the Kingdom of Saudi Arabia' declared by King Abdul-Aziz Al-Saud. Petroleum oil was found in Saudi Arabia on 3 March in 1938, which made the country rich since the export of oil started to bring in a lot of money.
But the history of the Arabian Peninsula contains more history, which led to the development of the Saudi state. Inhabitants and cultures can be traced back 63,000 years ago. The most significant event that happened in the Peninsula is the rise of the Islamic religion presented by Prophet Muhammad. The Rashidun Caliphate, Umayyad Caliphate, Abbasid Caliphate and Fatimid Caliphate all occupied the Arabian Peninsula and thus helped it develop to how we know it today. More dynasties were there in history, but the Islamic holy cities of Mecca and Medina were under the protection of the Hashemite Sharifs of Mecca from the 10th century onwards.