Gislason was born in county Reykjahverfi in district South
Thingeyjasýsla, but lived in many parts of the country. The late
Arcaeologis and president, Kristjan Eldjarn, wrote the book "Arngrimur
the Painter", which depicts this remarkable man extremely well in his
deep rooted agricultural society.
He was and is considered one of the best uneducated painters of the
country. He specialised in portraits and altar pieces. He
was a poor man, but succeeded in adding his workshop to his farm
Gullbringa in 1884. Two of the sides were built of turf and
stones and the workshop has a sod roof. It is the oldest
preserved workshop of a painter in the country. The Central Bank
of Iceland financed its restoration in 1983 to commemorate the late
president. Since then, it has been under the protection of the
National Museum of Iceland.