The flag of Saudi Arabia, which is not allowed to be flown at half-mast because of the important religious verse written on it - there was also an outcry when the flag was printed on a promotional FIFA soccer ball because kicking the flag is blasphemy
The CIA World Factbook's map of Saudi Arabia
Saudi Arabia is known for its desert climate and enormous oil reserves; it is the largest country in the world not to contain any rivers. (Many of the nation's borders were never properly surveyed or defined until quite recently, because they passed through the famous Rub Al-Khali desert. With no permanent population, there was no point drawing a border.) The nation is also the birthplace of Islam, and all Muslims who can afford it are obligated to go on a pilgrimage (the "hajj") to the holy city of Mecca at least once in their lives. (However, it is recorded that 1,389,053 pilgrims came in 2014, out of a global total of 1,620,000,000 Muslims: so it seems as if not everybody has the means or the inclination to make the trip.) Non-Muslims cannot become Saudi citizens, women cannot enter Saudi Arabia without a male husband or chaperone, and citizens of Israel are not allowed to enter the country at all. Even having an Israeli stamp in your passport may get you into trouble.
In about the year 570, the prophet Muhammad was born in Mecca, but eventually he and his followers were forced to leave to Medina in 622 - this event marks Year 0 of the Hejira ("Flight") calendar used by most Arabic Muslim countries. In 629, he returned to Mecca, and by 632 (when he died of an illness) most of Arabia was under his control. Both of those cities lie in Saudi Arabia, so the country has great religious significance. Mecca contains the holiest site in Islam - the Ka'aba ("cube" - self-explanatory, really), which is surrounded by the Masjid al-Haram ("the sacred mosque"). Every year, the Masjid al-Haram fills up with millions of hopeful pilgrims in one of the world's largest annual gatherings.
Although early Islamic history is important, when we discuss Saudi Arabia, we are mainly concerned with the 20th and 21st centuries - the modern Saudi state was only founded in 1932. Numerous caliphates existed throughout history - countries that housed a caliph, an individual considered to be a successor to Muhammad and Islam's widely accepted highest religious authority - but no such country has existed since the fall of the Ottoman Empire after World War I. At that point, the Arabian Peninsula, once the center of great Muslim empires, was divided into a collection of poor and petty emirates. The royal house of Saud, an exiled family with no territory, managed to gather some troops and capture Riyadh in 1902 in a very small battle - the total number of combatants on both sides was just 148. (At the time, not very many people lived in the desert.) By 1921, the Sauds had captured more territory and established the Sultanate of Nejd - by 1927, they took nearby Hejaz and set themselves up as Kings of Hejaz and Nejd, a dual monarchy. In 1932, the two halves were united into the Kingdom of Saudi Arabia, headed by Abdulaziz Ibn Saud. Ibn Saud went on to have dozens of children, and the House of Saud is now one of the world's largest royal families - a useful asset when you are running one of the world's last truly absolute monarchies. (The country is still ruled by Ibn Saud's elderly children.) Saudi Arabia is one of only three countries in the world that does not claim to be democratic - incredibly, it has set itself up as one of the closest allies of the United States.
Saudi Arabia was one of the poorest countries on Earth, with few natural resources and hostile, dry terrain. This all changed with the discovery of the world's largest reserves of oil in 1938.
A Saudi half qirsh from 1937
The Kingdom has since gained a reputation for being filthy rich, bankrolling all kinds of enterprises and employing all kinds of money-related tactics: protests in 2011 were successfully put down with more than $100,000,000,000 in benefits for Saudi citizens. Perhaps this explains why this undemocratic nation is best friends with the United States. Although the nation has a population of just 31 million, it reportedly spends more on defense than Russia does! More than 10% of the nation's GDP goes to the military... or so they say. I was the only kid in junior high school to never go through a guns and war phase, so I have to admit that I find most military figures perplexing.
Saudi Arabia is also known for its austere religious philosophy (for instance, women cannot get drivers' licenses in the "Magic Kingdom"). Although the country has slowly been re-examining many of its hyper-conservative practices, Saudi coins usually depict nothing but Arabic calligraphy on them, making life difficult for anyone who wishes to identify and catalogue their Saudi collection. The only pictoral design seen on Saudi coins is the country's distinctive emblem:
Until 1960, Saudi Arabia used a confusing pre-decimal system, with 22 qirsh making 1 riyal. After that, the currency was decimalized, with 100 halala equaling 20 qirsh equaling 1 riyal. 1 Saudi riyal is today worth about USD $0.27. Decimal Saudi currency has not experienced any significant design change since the 1970s, and it is often quite difficult to tell different types apart.
Coins from the reign of Faisal bin Abdulaziz Al Saud, 1964-1975
Coins from the reign of Khalid bin Abdulaziz Al Saud, 1975-1982
This coin is an FAO commemorative, but you wouldn't know it if you don't know Arabic.
Coins from the reign of Fahd bin Abdulaziz Al Saud, 1982-2005
A Saudi riyal note with King Fahd on it.
A coin from the reign of the recently departed Abdullah bin Abdulaziz Al Saud, 2005-2015
The current Saudi king is Salman bin Abdulaziz Al Saud, who has been in power for only seven months - Numista currently does not list any coins struck in his name.
Saudi Arabia has made another indirect contribution to numismatics. Because the country attracts so many pilgrims every year, special banknotes exist from both India and Pakistan (both nations have large Muslim populations) to be used by Indian and Pakistani pilgrims in Saudi Arabia - the Indian issues are printed in unusual colours, while the Pakistani issues say "FOR HAJ PILGRIMS FROM PAKISTAN FOR USE IN SAUDI ARABIA ONLY" (this website has nice pictures).
Numista page for Hejaz
Numista page for Saudi Arabia
