• He was a Dutch Renaissance painter, active in Sweden.
• No signed works by his hand survive.
• He is thought to have been born in either Antwerp or Utrecht.
• He was active in Sweden, from 1562 as court painter.
• Several portraits have been attributed to him, notably portraits of King John III of Sweden, dowager Queen Catherine Stenbock and the future King of Poland and Grand Duke of Lithuania, Sigismund III Vasa.
• Johan Baptista van Uther taught and influenced court portraitist Holger Hansson and, possibly, Cornelius Arendtz.