San Marino Established – 301 CE (AD)
The official name of this tiny country is “Most Serene Republic of San Marino.” It claims to be the oldest recorded sovereign state, established on this day in the year 301 by a stonecutter named Marinus of Rab. The country is named after Marinus, who was made a saint in the Catholic church. (San means “saint.”)
Centuries later, in 1600, San Marino adopted a constitution. This is the oldest constitution that is still in use.
When I said that San Marino is a tiny country, I mean tiny: the microstate is just 24 square miles (or 61 square kilometers) in area, with a population of around 30,000 people. Strangely, it is only the third smallest nation in Europe (Monaco and Vatican City are smaller).
San Marino is a bubble within Italy—in other words, it is completely surrounded by Italy. The official language is Italian, and the nation uses the Euro as money, just like Italy. I am not sure why it did not join up with Italy in the 19th century, when the rest of the states in the Italian peninsula unified, but I read that it wished to remain independent and was able to convince certain powerful people that it should be allowed to do so.
The government of San Marino made U.S. President Abraham Lincoln an honorary citizen.
By the Way...
In the past, it has been common in many countries to use BC and AD with dates, with the supposed date of the conception or birth of Jesus being the era marker, year “one.” (BC Means Before Christ, and AD means Anno Domini, or Year of Our Lord). However, since not all people in the world are Christian, and since some nations have state religions that are not Christianity, a date marker that isn't pointed to just one specific religion is needed.
As long ago as the 1500s and 1700s, some people began to use CE and BCE, for Common Era and Before Common Era, respectively. Today many style manuals urge their use, and some international organizations, textbooks, scholarly journals, and even Christian organizations use them as well. Wikipedia is said to use CE/BCE, but I saw many dates with BCE, many with BC, and none at all with either AD or CE...so I think Wikipedia dates are perhaps as various as its authors.
Even though to some extent the world has united around certain time and date conventions, there is a lot of variety in the world about era markers. Countries as diverse as China and Israel, when using Gregorian calendar dates, use CE/BCE. However, Japanese use “Western Calendar” rather than either AD or CE. Polish people typically use “Of Our Era”/”Before Our Era,” and Koreans use words that translate to “Western Era” and “Before the Origin of the Western Calendar.”