Thomas was the son of the pharmacist at Løveapoteket [Lion Pharmacy], so he grew up in a quite wealthy family in Trondheim. He was a pupil at Katedralskolen, where he demonstrated great diligence, and from where he graduated in 1697. In the same year he was matriculated into the University of Copenhagen. Here he had a rapid career: The next year he had already been awarded his first philosophical degree, and after two years he had finished his theological studies. He was then 17 years of age. During his stay in Denmark he was the private tutor for the Lorentz brothers and Thomas Angell, who all came to make their mark in the tutor's home town in Norway.
After his studies he spent some years in Helgeland, where he first became acquainted with the Sami population in the north. This meeting would come to change his life. In 1709 von Westen was appointed to the position of the vicar in Veøy in Romsdal. As a member of a Pietist religious movement he now worked actively to improve the life quality of the Sami, spiritually and materially.
As a result of this work a seminar was established in 1716 in Trondheim Katedralskole with the aim of training teachers and missionaries to work among the Sami. Thomas von Westen was appointed the "Sami lector" at this seminar. In the following years he made several long journeys in the high north, sacrificing his private life, fortune and health.
His best friend in Trondheim was the mayor, Hans Hagerup, who helped ensure his subsistence in his home town. Thomas von Westen, "the apostle of the Sami", died a poor and exhausted man in 1727. Two hundred years later a memorial plaque in his honour was unveiled in the transept of Nidaros Cathedral.
Recommended reading: Ivar Sæter: Thomas von Westen. 1926.