Second Special Squadron Mediterranean Campaign (1917–1918)

After the outbreak of the First World War Japan joined the Allies under the Anglo-Japanese Alliance. As German U-boat attacks on Mediterranean shipping intensified, the British government asked Japan on January 11, 1917 to send an escort force, and in February the Imperial Japanese Navy formed the Second Special Squadron (第二特務艦隊) under Sato Kozo. Drawn primarily from ships of the Sasebo Naval District, it initially consisted of the protected cruiser Akashi as flagship and eight Kaba-class destroyers: the 10th Destroyer Division (Kaede, Katsura, Ume, Kusunoki) and the 11th (Sakaki, Kashiwa, Matsu, Sugi). The squadron reached Malta on April 13, 1917. In the summer of 1917 the armoured cruiser Izumo took over as flagship and the 15th Destroyer Division (Momo, Kashi, Hinoki, Yanagi) arrived, bringing the destroyers to twelve; the squadron also manned two destroyers lent by Britain.

On May 4, 1917 the British troopship Transylvania, carrying about 3,000 officers and men and escorted by Matsu and Sakaki, was torpedoed by the German submarine U-63 off Savona, Italy. Matsu went alongside to take off troops while Sakaki circled to keep the submarine down; 412 people died, and English-language accounts credit the two destroyers with rescuing nearly 3,000 personnel, an action said to have defied the standing practice against stopping to rescue in U-boat waters. On June 11, 1917 Sakaki was torpedoed near Crete by the Austro-Hungarian submarine U-27; the forward third of the ship including the bridge was blown away and 59 men were killed, among them her captain, Commander Uehara Taichi. She was towed in, given emergency repairs at Piraeus and fully repaired at Malta in early 1918.

Over some eighteen months Japanese sources record 348 escort sorties, 788 warships and transports escorted (mostly British) and about 750,000 personnel carried (English sources say about 700,000), with more than thirty engagements with submarines. Figures for those rescued vary: 4,063 in some accounts, 7,075 in English Wikipedia. The squadron is said to have been at sea 72 percent of the time, the highest rate among the Allied Mediterranean fleets, earning it the title 'Guardian Deity of the Mediterranean'. From April to July 1918 it escorted the 'Big Convoy' troop movements that reinforced the Western Front. It returned to Japan on July 2, 1919, bringing seven German submarines as prizes.

The dead of Sakaki are buried in Kalkara Naval Cemetery, Malta. According to Japanese sources the memorial erected on June 9, 1918 commemorates 73 men, the 59 from Sakaki and 14 who died of other causes (English sources give 68). Crown Prince Hirohito paid his respects there in 1921 and Prime Minister Abe Shinzo in 2017. In Sasebo the Victory Memorial Hall was later built to commemorate these achievements.