1811
I found that "Regency Era: Regency Error?" by George Kachinsky was informative, but you have have some trouble getting a copy.
Year 0
The Regency Era
The swing era in jazz started in the year of 1935
1730 to 1820
About 1900, the first year of the 20th century.
It stared during the 1920's.
The romantic ere begun in the 1800's
1864
The period that came before the Regency Era in England was the Georgian Era, which included the reigns of the first four British monarchs of the House of Hanover - George I, George II, George III, and George IV. The Georgian Era is typically considered to span from 1714 to 1837.
Regency Centers Corporation (REG)had its IPO in 1993.
If by "Common Era" you are referring to the era name system, then Christianity coincided with the beginning of the Common Era. In fact, the Common Era is also known as the "Christian Era" or "Current Era". The year 1 CE is the year in which a 6th century monk estimated that Jesus had been born when he created the Common Era calendar.