In England and elsewhere in Europe during the Middle Ages this name was used in honour of the saint. However, it was not generally given in Ireland before the 17th century because it was considered too sacred for everyday use. It has since become very common there.
Apart from royalty, this name was only moderately popular in France during the Middle Ages. After the French Revolution, when Louis XVI was guillotined, it became less common.
The Normans brought the name to England, where it was usually spelled Lewis, though the spelling Louis has been more common in America. Famous bearers include French scientist Louis Pasteur (1822-1895), French actor Louis de Funès (1914-1983), Scottish author Robert Louis Stevenson (1850-1894), who wrote Treasure Island and Dr Jekyll and Mr Hyde, and American jazz musician Louis Armstrong (1901-1971).
In some cases this name can be a short form of longer names that start with Leo, such as Leonard.
A famous bearer was Jesse James (1847-1882), an American outlaw who held up banks and stagecoaches. He was eventually shot by a fellow gang member for a reward. Another famous bearer was the American athlete Jesse Owens (1913-1980), whose real name was James Cleveland (or J. C.) Owens.
Heinrich was popular among continental royalty, being the name of seven German kings, starting with the 10th-century Henry I the Fowler (the first of the Saxon kings), and four French kings. In France it was usually rendered Henri from the Latin form Henricus.
The Normans introduced the French form to England, and it was subsequently used by eight kings, ending with the infamous Henry VIII in the 16th century. During the later Middle Ages it was fairly popular, and was generally rendered as Harry or Herry in English pronunciation. Notable bearers include arctic naval explorer Henry Hudson (1570-1611), American-British novelist Henry James (1843-1916), American automobile manufacturer Henry Ford (1863-1947), and American actor Henry Fonda (1905-1982).
As a given name, it was used on the American sitcom Murphy Brown (1988-1998) for both the mother and son of the main character. By 1998 it was more popular as a name for girls in the United States, perhaps further inspired by a character from the movie Jerry Maguire (1996).
As an English name it can also derive from the month of August, which was named for the Roman emperor Augustus.
The name has been used by kings of Scotland, Poland and Yugoslavia, emperors of Russia, and eight popes. Other notable bearers include English poet Alexander Pope (1688-1744), American statesman Alexander Hamilton (1755-1804), Scottish-Canadian explorer Alexander MacKenzie (1764-1820), Russian poet Alexander Pushkin (1799-1837), and Alexander Graham Bell (1847-1922), the Scottish-Canadian-American inventor of the telephone.