This was the name of two ruling queens of Portugal. It was also borne by the Habsburg queen Maria Theresa (1717-1780), whose inheritance of the domains of her father, the Holy Roman emperor Charles VI, began the War of the Austrian Succession.
After the Norman Conquest this name became common in England. It was revived in the 18th century, perhaps in part due to Matthew Prior's 1709 poem Henry and Emma [2]. It was also used by Jane Austen for the central character, the matchmaker Emma Woodhouse, in her novel Emma (1816).
In the United States, it was third in rank in 1880 (behind only the ubiquitous Mary and Anna). It declined steadily over the next century, beginning another rise in the 1980s and eventually becoming the most popular name for girls in 2008. At this time it also experienced similar levels of popularity elsewhere, including the United Kingdom (where it began rising a decade earlier), Germany, France, Italy, Spain, Scandinavia and the Netherlands. Famous bearers include the actresses Emma Thompson (1959-), Emma Stone (1988-) and Emma Watson (1990-).
As a given name, Diana has been regularly used since the Renaissance. It became more common in the English-speaking world following Walter Scott's novel Rob Roy (1817), which featured a character named Diana Vernon. It also appeared in George Meredith's novel Diana of the Crossways (1885). A notable bearer was the British royal Diana Spencer (1961-1997), the Princess of Wales.
Due to the popularity of the saint, the name became common in the Christian world during the Middle Ages. The Normans brought it to England, where it was commonly spelled Cecily — the Latinate form Cecilia came into use in the 18th century.