Ennoblement
The date and circumstances of his ennoblement are not clear. While it is undisputed that he called himself and was referred to as von or de Martens in publications since the early 1870s, this title might have been bestowed upon him either with one of the more distinguished Russian Orders, or with the title of a Privy Councillor (according to the Table of Ranks), or simply with his appointment as a full professor. He was never registered in the matricles of the knightage of Livonia (Livländische Ritterschaft) or one of the other three Baltic knightages (that is of Estonia, Courland and Ösel/Saaremaa). His surname, Martens, is included in the Russian Heraldic Book #14, though it is uncertain if this entry relates to him or to another noble of the same name. His social advancement was the more remarkable, as it was exclusively based on his professional merits.
Read more about this topic: Friedrich Martens