27th June 1917
Southern Front
Austrian attack on Agnello pass repulsed.
Naval and Overseas Operations
French cruiser "Kleber" sunk by mine.
British transport "Armadale" sunk in Atlantic.
The Doxa, a Greek destroyer seized by the French Navy, is attacked and sunk by the German submarine UB-47, resulting in 29 deaths.
Aviation
German ace Leutnant Karl Allmenröder is shot down and killed. His 30 victories will tie him with five other pilots as the 28th-highest-scoring German ace of World War I.
Political, etc.
Greek declaration of 23 November 1916 becomes effective; state of war v. Austria-Hungary and Turkey declared.
Ship Losses:
Armadale (United Kingdom) The cargo ship was torpedoed and sunk in the Atlantic Ocean 160 nautical miles (300 km) north west of Tory Island, County Donegal (56°17′N 12°42′W) by
SM U-60 ( Kaiserliche Marine) with the loss of three crew.
Baltic (Sweden) The auxiliary barge was sunk in the Arctic Sea 75 nautical miles (139 km) west of Holmengrå, Finnmark, Norway by
SM U-21 ( Kaiserliche Marine).
Baron Ogilvy (United Kingdom) The cargo ship was torpedoed and sunk in the Atlantic Ocean 172 nautical miles (319 km) north west of Tory Island by
SM U-93 ( Kaiserliche Marine) with the loss of two of her crew.
Doxa (Hellenic Navy) The Niki-class destroyer was torpedoed and sunk in the Aegean Sea off Milos by
SM UB-47 ( Kaiserliche Marine).
Kléber (French Navy) The Dupleix-class cruiser struck a mine laid by
UC 61 (Georg Gerth) and sank in the Bay of Biscay off Brest, Finistère with the loss of 42 of her crew.
Indrani (United Kingdom) The cargo ship was torpedoed and sunk in the Atlantic Ocean 36 nautical miles (67 km) south west of the Tuskar Rock, Ireland by a Kaiserliche Marine submarine.
Longbenton (United Kingdom) The collier was torpedoed and sunk in the North Sea 12 nautical miles (22 km) off Flamborough Head, Yorkshire (53°55′N 0°03′W) by
SM UC-63 ( Kaiserliche Marine). Her crew survived.
Solway Prince (United Kingdom) The coaster was scuttled in the English Channel 8 nautical miles (15 km) north of Alderney, Channel Islands by
SM UB-40 ( Kaiserliche Marine). Her crew survived.
Tong Hong (United Kingdom) The cargo ship was sunk in the Mediterranean Sea 55 nautical miles (102 km) south by west of Cape Sicie, Var, France (42°09′N 5°40′E) by
SM U-63 ( Kaiserliche Marine). Her crew survived, but her captain was taken as a prisoner of war. The rest of the survivors were rescued by Vega ( French Navy).
Ultonia (United Kingdom) The cargo liner was torpedoed and sunk in the Atlantic Ocean 190 nautical miles (350 km) south west of the Fastnet Rock by
SM U-53 ( Kaiserliche Marine) with the loss of a crew member.