The Battle of Gangut (Russian: Гангутское сражение, Finnish: Riilahden taistelu, Swedish: Slaget vid Rilax or Sjöslaget vid Hangö udd) took place on 27 July during the Great Northern War (1700–21), in the waters of Riilahti Bay, north of the Hanko Peninsula, near the site of the modern-day city of Hanko, Finland, between the Swedish Navy and Imperial Russian Navy.
It was the first important victory of the Russian fleet in its history. Less than 1000 Swedish soldiers were fighting and 361 of them were killed. The Russians where about 4000 and 469 were killed or wounded.
The Russian Tsar, Peter I, had begun his offensive in Finland in the spring of 1713. The Russian armies quickly advanced all the way to Turku on the southwestern coast of Finland. With Russian victory in the battle of Storkyro on 19 February 1714, Peter I left southern Finland fully in Russian control. The Russian governor in Finland, Prince Mikhail Galitzine, with his headquarters in Turku, was unable to receive support by sea, which back then was far more important than land-based support, as Swedish battle fleet under Admiral Gustav Wattrang had started blockading the coastal sea route past Hanko Peninsula already on 24 April. While it also blockaded the Russian supply route the blockade also prevented the Russian coastal fleet from reaching Sweden and raiding the Swedish coast. First Russian transports left from Helsinki in early May, but had to stop east of Hanko to Tammisaari, where the supplies needed to be hauled overland. Russian attempts to provide ships to west of Hanko ended when newly formed Swedish coastal squadron led by Captain Anton Wrangel intercepted the Russian supply ships south of Turku on 10 May, and in one sided engagement sunk most of them while the rest were scattered. Admiral Apraksin’s fleet was sent from its base at Kronstadt by the Tsar to open these service lines.
When the 80 ship strong Russian galley fleet arrived near the peninsula on 29 June 1714 they were met by a strong Swedish naval fleet consisting of 16 ships of the line and 7 smaller ships under the command of Admiral Wattrang. Apraksin decided to withdraw his ships farther away to the eastern side of the peninsula and call for reinforcements while he waited for the further 20 galleys to arrive from Helsinki where they had been over the winter. The majority of the troops in Turku were moved according to his request to the peninsula. A plea for help was also sent to the Tsar, who was with the rest of the Baltic Fleet in Reval (Tallinn). Admiral Apraksin specifically let the Tsar know that he should come personally to lead the attack. Russian battle fleet of 10 ships of the line and 6 frigates was originally intended to participate to the breakthrough attempt at Hanko but upon inspecting the fleet Tsar found it ill prepared for battle and abandoned the use of the battle fleet. Further he ordered that fleet should not engage unless it would have clear superiority in artillery. Peter I reached the Russian coastal fleet on 20 July.
The first attempt in breaking through the Swedish lines was made by attempting to pull the galleys over the peninsula. The friction was reduced using ox skins between the ground and the ships. The first galley was successfully pulled over with much trouble, but the second was damaged, and the attempt was subsequently abandoned. However, Admiral Wattrang had been informed of the Russians’ attempt, and he sent a small naval detachment consisting of 11 ships led by Schoutbynacht (equivalent of a Rear Admiral) Nils Ehrenskiöld to intercept the Russians. Swedish efforts forced Russians to abandon their plans few days later.
The second attempt by the Russians took advantage of the calm weather on the morning of 26 July. The small galleys were easily maneuvered, whereas it was exceedingly difficult to try to turn the heavy Swedish battleships in such a weather. Apraksin initially sent 20 small galleys which succeeded in running the blockade and then as Swedes started towing their sailing ships further out to sea with rowing boats he sent 15 further galleys to the same route though the second group had to go much further around since Swedes had moved away from the immediate vicinity of the coast. With Wattrang’s fleet moved outwards in an attempt to block the Russian breakthrough, the Russians started their blockade run on early hours of 27 July along the now clear sea route just alongside the cape. Despite of frantic Swedish efforts to stop the Russians only few of the Swedish ships reached firing range and even then their artillery fire had very little effect. Only one galley was lost when it ran aground. Now only Ehrenskjöld’s small coastal squadron stood between Russian coastal fleet, the maze like archipelago of Aland, and south western Finland.
Swedish battle fleet which had been blockading Hanko Peninsula was quickly moved to west of land to protect Sweden against the raids by Russian galleys. This also opened the coastal seaway for the Russian transports. Russian galley fleet under Admiral Apraksin started from Rilax on 1 August to sail towards Turku from where he continued already on 5 August towards Aland. By 8 August Apraksin reached the east coast of Aland triggering Swedish withdrawal from the islands. On 13 August whole of Aland was under Russian control. As the Swedish battle fleet prevented Apraksin from reaching Sweden the galleys were diverted to support the Russian army fighting along the coast of Gulf of Bothnia with small squadron plundering and razing the Swedish town of Umeå on 18 September. Presence of the Russian galley fleet on Bay of Bothnia forced the remnants of the Swedish army in Finland to hastily withdraw to Torne River to avoid getting encircled.