SMS Szent István

She was the fourth and last Tegetthoff-class dreadnought and the only one built in the Hungarian half of the empire — a concession for Hungarian support of the 1910 and 1911 naval budgets that funded the class. Ganz-Danubius laid her down at Fiume on 29 January 1912. Fiume was the only large Hungarian shipyard, and had built nothing but smaller merchant vessels for firms like the Austrian Lloyd; the yards had to be refitted and enlarged before they could take a hull this size.

Her main battery was twelve 45-calibre 30.5 cm Škoda K10 guns in four triple turrets, superfiring fore and aft — among the few parts of her built outside Hungary, coming from the Škoda Works at Plzeň. Triple turrets kept the citadel short and the displacement down while delivering a heavier broadside than dreadnoughts of comparable size, and answered the triples of the Italian Dante Alighieri. Twelve 15 cm guns sat in casemates amidships, with eighteen 7 cm guns on open pivots above them.

Unlike her sisters she had two shafts rather than four, driven by AEG-Curtis turbines on twelve Babcock & Wilcox boilers — 48 tonnes heavier than the sisters' Yarrow boilers, but able to hold top speed for eight hours instead of two. Her belt was 280 mm through the citadel. The underwater protection measured only 1.60 metres in total thickness, too shallow to contain a torpedo or mine detonation without rupturing — the flaw that killed both her and Viribus Unitis.

Austria-Hungary had built for coastal defence for most of the nineteenth century, and the navy had little public support until Archduke Franz Ferdinand was made an admiral in September 1902. He backed expansion because he read Italy as the empire's chief regional threat; in 1903 Italy had eighteen battleships in commission or under construction against six Austro-Hungarian. Montecuccoli's memorandum to Franz Joseph I in January 1909 proposed four dreadnoughts of 20,000 tonnes, one of which became Szent István.

The memorandum leaked to Italian newspapers, and Italy laid down Dante Alighieri that June. With Budapest lacking a prime minister and therefore a budget, the Witkowitz Ironworks and the Škoda Works offered to begin building at their own financial risk against assurances of later purchase, and the Rothschilds in Austria secretly financed two of the ships, Franz Ferdinand personally courting Albert Salomon Anselm von Rothschild. The Social Democrats' Arbeiter-Zeitung broke the story in April 1910, by which time the design was settled.

London read the ships as something else entirely — "a concealed addition to the German fleet", repayment for German diplomatic cover over Bosnia. A British agent was sent to Berlin when Montecuccoli asked Tirpitz for recommendations on the design, and Ambassador Cartwright put the rumours to Foreign Minister Aehrenthal, who denied any dreadnoughts were building. Churchill, appointed First Lord in 1911, rejected the idea of Austro-German collusion. Szent István was projected to cost over 60 million krone, against 40 million for a Radetzky.

Commissioned into the 1st Battleship Division in December 1915 after gunnery and machinery trials that touched an unofficial 21 knots, she came too late for the bombardment of Ancona and found a war with nowhere to go. The Otranto Barrage closed the Adriatic, and Grand Admiral Anton Haus kept his dreadnoughts at Pola as a fleet in being — criticised by the army and by Berlin, but drawing Entente forces to the strait that might otherwise have gone to Gallipoli.

Coal decided as much as doctrine: 75% of the navy's coal had come from Britain before the war, and what remained was held for a major operation or an Italian attack. Between 1916 and 1918 she rarely left harbour except for gunnery practice in the Fasana Strait, spending 54 days at sea in 937 days of service — 5.7% of her life — and making a single two-day trip to Pag Island. She was never dry-docked to have her bottom cleaned.

Her set-piece occasions were inspections. Emperor Karl I boarded her in December 1916, and returned in June 1917 for the first formal imperial review of the navy since 1902, with crews crowding the decks and the ensign flying from every ship; Wilhelm II inspected her in December 1917 while visiting the German submarine base. Otherwise the war reached Pola as more than eighty air raids by the newly formed Italian air arm.

Miklós Horthy took command of the fleet in 1918, exercised it hard, and planned a full attack on the Otranto Barrage with all four Tegetthoffs as the heart of the assault. He took Viribus Unitis and Prinz Eugen south on 8 June; Szent István and Tegetthoff followed on the evening of the 9th. Pushing to catch up, Szent István overheated her turbines, had to drop to 12 knots, and made an excess of smoke when steam was raised again.

At about 3:15 a.m. on 10 June two Italian MAS boats returning from an uneventful patrol saw that smoke. The unit was commanded by Luigi Rizzo, who had sunk the coastal defence ship Wien at Trieste six months earlier. MAS-21 attacked Tegetthoff and missed; MAS-15 put two 45 cm torpedoes into Szent István abreast her boiler rooms at 3:25. The aft boiler room flooded and she took a ten-degree list, cut to seven by counter-flooding; collision mats failed to plug the holes.

Water reached the forward boiler room and doused all but two boilers, killing the power for the pumps. The turrets were trained to port and their ready ammunition thrown overboard; Tegetthoff's attempt at a tow failed. Crewmen gathered on the high side as counterweight, the chaplain gave a final blessing, and Tegetthoff's men came onto their decks to salute. She capsized off Premuda at 6:12 a.m. with 89 dead, 41 of them Hungarians; her captain, Heinrich Seitz, was thrown from the bridge and saved.

An officer of Tegetthoff and an official film crew both recorded her last half hour. The two films were spliced together and exhibited in the United States after the war, the proceeds used to feed children in Austria. She is one of only two battleships whose sinking on the high seas was ever filmed, the other being HMS Barham in the next war. Horthy, believing his plan betrayed, called off the raid — in fact the MAS boats had been on routine patrol and knew nothing of it.

Rizzo received his second Gold Medal of Military Valor and a knighthood in the Order of the Crown of Italy, and MAS-15 was installed in the Monument to Vittorio Emanuele II in Rome. The Italian navy still keeps 10 June as its Navy Day. The Yugoslav Navy located the wreck in the mid-1970s, upside down at 66 metres, her bow broken off but lying immediately alongside the encrusted hull, the two torpedo holes visible in her side. She remains the largest ship Hungary ever built.