From the Gaelic name Niall
, which is of disputed origin, possibly meaning "champion" or "cloud". This was the name of a semi-legendary 4th-century Irish king, Niall of the Nine Hostages.
In the early Middle Ages the name was adopted by Viking raiders and settlers in Ireland in the form Njal
. The Vikings transmitted it to England and Scotland, as well as bringing it back to Scandinavia. It was also in use among the Normans
, who were of Scandinavian origin. A famous bearer of this name was American astronaut Neil Armstrong (1930-2012), the first person to walk on the moon.