He was born in Antwerp to a family of sculptors, and was first trained
by his father. He soon left for London and in 1746 moved on to Paris,
where he entered the workshop of the sculptor René Michel Slodtz (1705-64).
Once in Berlin, he became court sculptor, also being appointed director
of the Academy of Arts and head the royal sculptural workshop.
best known as a master of mythological genre sculpture, and besides numerous
portraits did many allegorical pieces clearly showing the transition from
Rococo to early Neoclassicism. In his few large-scale works, such as those
of generals Seydlitz and von Keith, he was one of the first sculptors
to show men not in the robes of the Antiquity, but in contemporary clothing.
Tassaert developed a Rococo-Neoclassicism, transmitted via influences
from Britain, that coincided with the taste of the time. As a professor
at the school of sculpture in Berlin, his naturalistic, objective approach
had a particularly notable influence on his pupil and successor Johann
Gottfried Schadow, thereby setting the tone for the Prussian sculptural
tradition of the whole 19th century.