There is almost no mention of sean-nós songs in medieval Irish literature, but experts have speculated that sean-nós singing has existed in a similar form since the thirteenth century. The tradition of sean-nós song was exclusively oral, and remains customarily so, however a few songs were known to have been conveyed to script as early as the 16th century. A songbook for Elizabeth I contained English interpretations of sean-nós songs. When Oliver Cromwell expelled the Irish Catholic people to Connacht in the seventeenth century, different regional song forms were combined to form what sean-nós is today. Songs started to be more extensively written down in the eighteenth century and distributed in print from then on. The use of the term "sean-nós" to describe this type of singing was coined in the early 1940s at the Gaelic League Oireachtas.