Ingersoll is a surname derived of the Old Norse words "Ingvar" or "Inger" and "sál", common words in found in modern Icelandic, Swedish and Norwegian.
[1] Surnames derived from Old Norse have changed over time due to the splitting of the language into modern Icelandic, Norwegian, Swedish, Greenlandic, Faroese and Danish[2] as well as names being changed with immigration into new countries like the United States.
[3] This surname has split over time into some of these common spellings: Ingersoll, Ingersöll, Ingersol, Ingersole, Ingvarsson, Ingersson, Inkersoll, and Ingwersol.
During the Viking Age, from the late 8th century to the mid-11th century, the Old Norse language expanded through Europe as the Vikings conquered and settled areas like Normandy (Normanni in Old Norse) and Inkersall (Ingvarsál in Old Norse).
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