SMS Frithjof was the third vessel of the six-member Siegfried class of coastal defense ships (Küstenpanzerschiffe) built for the German Imperial Navy.

General Leo von Caprivi, the new Chef der Admiralität (Chief of the Admiralty), requested a series of design proposals, which ranged in size from small 2,500 t (2,461-long-ton) coastal defense ships to heavily armed 10,000 t (9,800-long-ton) ocean-going battleships.

Caprivi ordered ten coastal defense ships to guard the entrances to the canal, since even opponents of the navy in the Reichstag (Imperial Diet) agreed that such vessels were necessary.

For defense against torpedo boats, the ship was also equipped with a secondary battery of eight 8.8 cm (3.5 in) SK L/30 guns in single mounts.

The ship was completed in November 1892 and began sea trials before being formally commissioned in Wilhelmshaven on 23 February 1893, under the command of Korvettenkapitän (KK—Corvette Captain) August Gruner.

She was assigned to II Division of the Maneuver Fleet, though she was still completing her trials, which prevented her from joining the unit for training exercises in March.

During the first, Frithjof and the other capital ships performed as the hostile French fleet, which was "attacked" by torpedo boats in the North Sea.

[6][7] In February 1894, Frithjof had her crew reduced while in reserve and she was allocated as a tender under the command of Kapitänleutnant (Captain Lieutenant) Ludwig Bruch, though this was only a temporary measure.

In April her crew was replenished to allow the ship to take part in training maneuvers with the rest of II Division; at that time, KK August Carl Thiele relieved Bruch.

[5] The year 1895 followed the same pattern as before, after the ship's crew was replenished in March under the command of KK Georg Alexander von Müller.

The normal peacetime training routine was interrupted in June by the opening of the Kaiser Wilhelm Canal, which was marked with a large naval review.

Frithjof's activity in 1896 repeated that of previous years, with KK Carl Derzewski in command, though on 14 November she resumed her role as the Reserve Division flagship.

The next two years passed similarly uneventfully beyond the normal training routine; the only event of note during this period was a cruise to Norway in 1898.

After the fleet maneuvers ended in September, Frithjof was transferred to the Reserve Squadron and allocated to the Naval Artillery Inspectorate for use as a training ship.

In July, she and the coastal defense ship Ägir conducted experiments with equipment to measure weather and air currents.

The ship's activity for the year concluded with the annual fleet maneuvers; KK Max Witschel thereafter took command of the vessel.

In 1906, Frithjof followed a similar routine to the previous year, operating with the Training Unit in the Baltic and North Seas and then with the combined fleet in August and September.

The year 1908 passed quietly for Frithjof; in September, after the annual maneuvers, KK Ferdinand Bertram replaced Hollweg.

[9] Following the outbreak of war in July 1914, Frithjof was recommissioned on 12 August under the command of Fregattenkapitän (Frigate Captain) von Lessel.

After the ships were prepared for operations, they were deployed to Germany's North Sea coast on 14 September; five days later, Frithjof was stationed in the mouth of the Ems, where Lessel took command of the local defense forces.