She was built by the naval shipyard in Pola; she was laid down in March 1855, was launched in October 1858, and was completed the following year.

Kaiser did see action during the Seven Weeks' War two years later, during which she took part in the Battle of Lissa as the flagship of Anton von Petz, commander of the Austrian 2nd Division.

In 1869, the Austro-Hungarians decided to rebuild Kaiser into an ironclad casemate ship; the work lasted until 1873, and was delayed significantly by budget shortfalls, which slowed the acquisition of armor plate from British firms.

Starting in the early 1850s, the Austrian Empire, faced with a strengthening Kingdom of Sardinia—which unified most of the Italian peninsula in a decade—began to modernize its navy with new steam-driven warships.

[3] But the modern naval historian Andrew Lambert states her length was 74.02 metres (242 ft 10 in) on 5,194 long tons (5,277 t).

[3] The ship was powered by a two-cylinder horizontal steam engine, which drove a single screw propeller that was 5.75 m (18.9 ft) in diameter.

[5][6][7] The keel of Kaiser was laid down on 25 March 1855 at the naval shipyard in Pola;[5] the ship was launched on 4 October 1858, and commissioned into the Austrian Navy in 1859.

She began sea trials on 6 December that year, with the first trip under her own power taking place from Muggia to Pola.

The now outnumbered Danish fleet remained in port for the rest of the war and did not seek battle with the Austro-Prussian squadron.

Instead, the Austrian and Prussian naval forces supported operations to capture the islands off the western Danish coast.

On 16 July, Persano took the Italian fleet, with twelve ironclads, out of Ancona, bound for the island of Lissa, where they arrived on the 18th.

[13] Persano then spent the next two days bombarding the Austrian defenses of the island and unsuccessfully attempting to force a landing.

Tegetthoff received a series of telegrams between 17 and 19 July notifying him of the Italian attack, which he initially believed to be a feint to draw the Austrian fleet away from its main bases at Pola and Venice.

He made a pass through the gap, but failed to ram any of the Italian ships, forcing him to turn around and make another attempt.

In the meantime, Petz took Kaiser and his division further south, hoping to attack the Italian wooden ships that had not joined the action.

Shortly thereafter, Kaiser rammed the ironclad Re di Portogallo in an attempt to protect the Austrian unarmored ships Erzherzog Friedrich and Kaiserin Elizabeth.

Though she missed with her ram, Affondatore did score a hit with one of her guns, badly damaging Kaiser, killing or wounding twenty of her crew.

[17] Kaiser had lost her foremast and funnel in the collision with Re di Portogallo, and Petz ordered his damaged ship to put into port at Lissa.

The Italian ships never came, and on 12 August, the two countries signed the Armistice of Cormons; this ended the fighting and led to the Treaty of Vienna.

[21] Chronic budgetary problems confronted the navy of the new Austro-Hungarian Empire; Tegetthoff had great difficulty securing funding for new ships to modernize the fleet.

[23] The ship was rearmed with a battery of ten 9 in (230 mm) 23-pounder muzzle-loading guns manufactured by Armstrong in a central, two-story casemate.

Kaiser was re-launched in 1871,[5] but further budgetary problems, particularly payments for the armor plate and iron fittings that were purchased from Britain, delayed completion of the conversion.

[25] On 11 February 1874, Kaiser joined the active squadron of the fleet, and became the flagship of Konteradmiral (Rear Admiral) Maximilian Daublebsky von Sterneck the following day.

Kaiser then departed from Frundsberg and visited a number of ports, including Cadiz, Malaga, Valencia, Gibraltar, and Tanger in Alawi Morocco.

While in Gibraltar, Kaiser met the screw corvette Fasana, and the two ships returned to Barcelona, were they joined Frundsberg and the gunboat Dalmat.