This name was common throughout the English-speaking world for most of the 20th century, though in the 1960s it began a slow decline in most places.
The name was borne by a semi-legendary 4th-century saint and martyr from Alexandria who was tortured on a spiked wheel. The saint was initially venerated in Syria, and returning crusaders introduced the name to Western Europe. It has been common in England since the 12th century in many different spellings, with Katherine and Catherine becoming standard in the later Middle Ages. To this day both spellings are regularly used in the English-speaking world. In the United States the spelling Katherine has been more popular since 1973.
Famous bearers of the name include Catherine of Siena, a 14th-century mystic, and Catherine de' Medici, a 16th-century French queen. It was also borne by three of Henry VIII's wives, including Katherine of Aragon, and by two empresses of Russia, including Catherine the Great.
As an English Christian name, Isaac was occasionally used during the Middle Ages, though it was more common among Jews. It became more widespread after the Protestant Reformation. Famous bearers include the physicist and mathematician Isaac Newton (1643-1727) and the science-fiction writer Isaac Asimov (1920-1992).
Because Elijah was a popular figure in medieval tales, and because his name was borne by a few early saints (who are usually known by the Latin form Elias), the name came into general use during the Middle Ages. In medieval England it was usually spelled Elis. It died out there by the 16th century, but it was revived by the Puritans in the form Elijah after the Protestant Reformation. The name became popular during the 1990s and 2000s, especially in America where it broke into the top ten in 2016.
This name was borne by a number of important saints, including Cyril of Jerusalem, a 4th-century bishop and Doctor of the Church, and Cyril of Alexandria, a 5th-century theologian. Another Saint Cyril was a 9th-century Greek missionary to the Slavs, who is credited with creating the Glagolitic alphabet with his brother Methodius in order to translate the Bible into Slavic. The Cyrillic alphabet, named after him, is descended from Glagolitic.
This name has been especially well-used in Eastern Europe and other places where Orthodox Christianity is prevalent. It came into general use in England in the 19th century.
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.
As an English name, Caleb came into use after the Protestant Reformation. It was common among the Puritans, who introduced it to America in the 17th century.