One half of the identical brother duo known as Marcus & Martinus who performs alongside his brother Marcus. They won the 11th season of Melodi Grand Prix Junior.
He and Marcus were just 10 years old when they competed in the Melodi Grand Prix Junior competition.
The brothers' winning song, "To dråper vann," on Melodi Grand Prix Junior 2012 peaked at #8 on the Norwegian Singles Chart. They would release other charting songs three years later called "Elektrisk" and "Ei som deg."
He and Marcus were born in Trofors, Norway. They also have a sister named Emma.
He and Marcus won Melodi Grand Prix Junior two years prior to Mathea-Mari Glittenberg.