Much of Kratzer's professional life was spent in England, where he was appointed as astronomer to King Henry VIII.

In the same manner as Holbein, Kratzer's talents obtained him a court position as astronomer and clock maker to the king.

Cratcherus) is recorded as a reader of Corpus Christi College, Oxford, where he is presumed to have taught mathematics.

[7][8] Peter Drinkwater has presented a critical evaluation of the sundials attributed to Kratzer, in particular the one in the Holbein portrait.

Nonetheless, Kratzer brought useful German skills and knowledge to the English court and was well-regarded over a period of nearly 30 years.