[3] In 1675, Ackermann moved to Tallinn and worked first in the workshop of Elert Thiele, a local woodcarver.
And that was a reason why between him and the guild's masters had begun a strong struggle which finished in court.
Ackermann won and got the permission to work alone, he was the first independent sculptor in Estonia[4] and acquired his own workshop at Toompea Hill.
He brought strong Central European influences to Northeast Europe, in particular the motifs of the Baroque and masterful Acanthus ornaments.
The majority of his works consists of almost twenty altarpieces, pulpits and large coat-of-arms epitaphs.