Carlyle's "History of Friedrich II of Prussia" BOOK VIII.
Page: 65

Seckendorf's, Crown-Prince there, in soldier's uniform again; a
completely pardoned youth. His uniform is of the Goltz Regiment,
Infantry: Goltz Regiment, which lies at Ruppin,--at and about, in
that moory Country to the Northeast, some thirty or forty miles
from Berlin;--whither his destination now is.

Crown-Prince had to resume his Kammer work at Custrin, and see the
Buildings at Carzig, for a three months longer, till some
arrangements in the Regiment Goltz were perfected, and finishing
improvements given to it. But "on the last day of February" (29th)
1732 being leap-year), his Royal Highness's Commission to be
Colonel Commandant of said Regiment is made out; and he proceeds,
in discharge of the same, to Ruppin, where his men lie. And so
puts off the pike-gray coat, and puts on the military blue one,
[Preuss, i. 69.]--never to quit it again, as turned out.

Ruppin is a little Town, in that northwest Fehrbellin region:
Regiment Goltz had lain in detached quarters hitherto; but is now
to lie at Ruppin, the first Battalion of it there, and the rest
within reach. Here, in Ruppin itself, or ultimately at Reinsberg
in the neighborhood, was Friedrich's abode, for the next eight
years. Habitual residence: with transient excursions, chiefly to
Berlin in Carnival time, or on other great occasions, and always
strictly on leave; his employment being that of Colonel of Foot, a
thing requiring continual vigilance and industry in that Country.
Least of all to be neglected, in any point, by one in his
circumstances. He did his military duties to a perfection
satisfactory even to Papa; and achieved on his own score many
other duties and improvements, for which Papa had less value.
These eight years, it is always understood, were among the most
important of his life to him.