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.
In the United States this name steadily grew in popularity through the 1950s and 60s. It shot up the charts after the release of the 1970 movie Ryan's Daughter. Within a few years it was in the top 20 names, where it would stay for over three decades. Famous bearers include the Canadian actors Ryan Reynolds (1976-) and Ryan Gosling (1980-).
In the New Testament Simon is the name of several characters, including the man who carried the cross for Jesus. Most importantly however it was borne by the leading apostle Simon, also known as Peter (a name given to him by Jesus).
Because of the apostle, this name has been common in the Christian world. In England it was popular during the Middle Ages, though it became more rare after the Protestant Reformation.