One of the perennial mysteries of Old Norse skaldic poetry is how skalds learned to compose such complex verses. The medieval Icelandic sagas feature a multitude of characters who compose skaldic poetry, many of whom appear to have been capable of improvising intricate skaldic verses in response to events that are happening around them, such as Egill Skalla-Grímsson, who even at the age of three is said to have improvised kenning-rich verses.