However, the appointment of Archduke Franz Ferdinand – heir to the Austro-Hungarian throne and a prominent and influential supporter of naval expansion – to the position of admiral in September 1902 greatly increased the importance of the Navy in the eyes of both the general public and the Austrian and Hungarian Parliaments.

[2][3] Franz Ferdinand's interest in naval affairs were largely motivated from his belief that a strong navy would be necessary to compete with Italy, which he viewed as Austria-Hungary's greatest regional threat.

Furthermore, a major scandal involving the Terni steel works' armor contracts led to a government investigation that postponed several naval construction programs for three years.

The most notable change in this memorandum compared to Monteccucoli's previous draft from 1905 was the inclusion of four additional dreadnought battleships with a displacement of 20,000 tonnes (19,684 long tons) at load.

[18] As a result, the largest shipbuilding enterprises in Austria-Hungary, the Witkowitz Ironworks and the Škoda Works, offered to begin construction on three Tegetthoff-class dreadnoughts at their own financial risk, in return for assurances that the Austro-Hungarian government would purchase the battleships as soon as funds were available.

After negotiations which involved the Austro-Hungarian joint ministries of foreign affairs, war and finance, the offer was agreed to by Montecuccoli, but the number of dreadnoughts constructed under this arrangement was reduced to two.

[19] In his memoirs, former Austrian Field Marshal and Chief of the General Staff Conrad von Hötzendorf wrote that due to his belief that a war with Italy in the near future was likely, construction on the battleships should begin as soon as possible.

He also worked to secure agreements to sell the ships to, in his words, a "reliable ally" (which only Germany could claim to be) should the budget crisis in Budapest fail to be settled quickly.

[20] Although smaller than the contemporary dreadnought and super-dreadnought battleships of the German Kaiserliche Marine and the British Royal Navy, Szent István was part of the first class of its type in the Mediterranean and Adriatic Seas.

This was done in order to rush the completion of the Radetzky-class battleships, though the looming construction of three other dreadnoughts in addition to Szent István meant the Austro-Hungarian Navy would likely have to ask the government for a yearly budget much higher than 100 million krone.

[23] A secret agreement to fund construction of Viribus Unitis and Tegetthoff, Szent István's sister ships, was struck with the Rothschild family in Austria, who owned the Witkowitz Ironworks, the Creditanstalt Bank, and had significant assets in both the Škoda Works and the Stabilimento Tecnico Triestino.

Archduke Franz Ferdinand personally courted Albert Salomon Anselm von Rothschild to obtain his family's monetary support until the government could buy Szent István's two older sister ships.

[25][26] Facing potential backlash over constitutional concerns that constructing two Tegetthoff-class battleships committed Austria-Hungary to spend roughly 120 million Krone without prior approval by either the Austrian Reichsrat or the Diet of Hungary, the deal remained secret.

The underwater protection system consisted of the extension of the double-bottom upwards to the lower edge of the waterline armor belt, with a thin 10-millimetre (0.4 in) plate acting as the outermost bulkhead.

[38] The Admiralty considered the rumored construction of the battleships "as a concealed addition to the German fleet", and interpreted the ships as Austria-Hungary's way of repaying Germany for her diplomatic support during the former's annexation of Bosnia in 1908.

[40] These concerns continued to grow and in April 1909, British Ambassador Fairfax Leighton Cartwright asked Austro-Hungarian Foreign Minister Alois Lexa von Aehrenthal about the rumored battleships.

At the time, the potential that Austria-Hungary was constructing a class of dreadnought battleships was widely regarded among the British press, public, and politicians as a provocation on the part of Germany.

[41] Neither the Admiralty's suspicions, nor those of some politicians, managed to convince Parliament that the German government was attempting to use the battleships to escalate Germany and Britain's already contentious naval arms race however.

[42] Roughly a year after Szent István's plans were drafted, Arbeiter-Zeitung, the Austrian Social Democratic Party newspaper, reported the details of the battleship to the general public.

Even so, the necessity of ensuring the Navy's most-important ships such as Szent István had the coal she needed in the event of an Italian or French attack or a major offensive operation resulted in the dreadnoughts remaining at port unless circumstances necessitated their deployment at sea.

By keeping Szent István and the Tegetthoff class battleships as a fleet in being, the Austro-Hungarian Navy would be able to continue to defend its lengthy coastline from naval bombardment or invasion by sea.

Furthermore, Italian ships stationed in Venice were effectively trapped by the positioning of the Austro-Hungarian fleet, preventing them from sailing south to join the bulk of the Entente forces at the Otranto Barrage.

[3] Miklós Horthy de Nagybánya, commander of Szent István's sister ship Prinz Eugen, was promoted to rear admiral and named Commander-in-Chief of the Fleet.

Horthy's strategic thinking differed from his two predecessors, and shortly after assuming command of the navy he resolved to undertake a major fleet action in order to address low morale and boredom, and make it easier for Austro-Hungarian and German U-boats to break out of the Adriatic into the Mediterranean.

Planning to repeat his successful raid on the blockade in May 1917,[64] Horthy envisioned a massive attack on the Allied forces with Szent István and the other three Tegetthoff class ships providing the largest component of the assault.

[66] En route to the harbour at Islana, north of Ragusa, to rendezvous with Viribus Unitis and Prinz Eugen for the coordinated attack on the Otranto Barrage, Szent István and Tegetthoff attempted to make maximum speed in order to catch up to the rest of the fleet.

The MAS unit was commanded by Capitano di corvetta Luigi Rizzo, who had sunk the Austro-Hungarian coastal defense ship SMS Wien in Trieste six months before.

The low death toll can be partly attributed to the long amount of time it took for the battleship to sink, and the fact that all sailors with the Austro-Hungarian Navy had to learn to swim before entering active service.

[72][73] After the war MAS-15 was installed in the Monument to Vittorio Emanuele II as part of the Museo del Risorgimento in Rome for the torpedo boat's role in the sinking of Szent István.

[37] Capitano di fregata Luigi Rizzo was awarded his second Gold Medal of Military Valor; his first was for sinking the pre-dreadnought battleship Wien in 1917, and appointed a knight of the Order of the Crown of Italy.