SM U-19 was a German Type U-19 U-boat built for the Imperial German Navy. Her construction was ordered on 25 November 1910, and her keel was laid down on 20 October 1911, at the Kaiserliche Werft Danzig. She was launched on 10 October 1912, and commissioned into the Imperial German Navy on 6 July 1913.
An armed merchantman is a merchant ship equipped with guns, usually for defensive purposes, either by design or after the fact. In the days of sail, piracy and privateers, many merchantmen would be routinely armed, especially those engaging in long distance and high value trade.
The Hague Conventions of 1899 and 1907 are a series of international treaties and declarations negotiated at two international peace conferences at The Hague in the Netherlands. Along with the Geneva Conventions, the Hague Conventions were among the first formal statements of the laws of war and war crimes in the body of secular international law. A third conference was planned for 1914 and later rescheduled for 1915, but it did not take place because of the start of World War I.
HMAS Pioneer was a Pelorus-class protected cruiser built for the Royal Navy at the end of the 19th century. She was transferred to the fledgling Royal Australian Navy (RAN) in 1912. During World War I, the cruiser captured two German merchant ships, and was involved in the East African Campaign, including the blockade of the cruiser SMS Königsberg and a bombardment of Dar-es-Salaam. She returned to Australia in late 1916 and was decommissioned. Pioneer was used as an accommodation ship for the following six years, then was stripped down and sold off by 1926. The cruiser was scuttled outside Sydney Heads in 1931.
Unrestricted submarine warfare is a type of naval warfare in which submarines sink merchant ships such as freighters and tankers without warning, as opposed to attacks per prize rules that call for warships to search merchantmen and place crews in "a place of safety" before sinking them, unless the ship shows "persistent refusal to stop ... or active resistance to visit or search". To follow the rules a submarine must surface, defeating the purpose of submarines and putting itself in danger of attack.
Portugal did not initially form part of the system of alliances involved in World War I and thus remained neutral at the start of the conflict in 1914. But even though Portugal and Germany remained officially at peace for over a year and a half after the outbreak of World War I, there were many hostile engagements between the two countries. Portugal wanted to comply with British requests for aid and protect its colonies in Africa, causing clashes with German troops in the south of Portuguese Angola, which bordered German South-West Africa, in 1914 and 1915. Tensions between Germany and Portugal also arose as a result of German U-boat warfare, which sought to blockade the United Kingdom, at the time the most important market for Portuguese products. Ultimately, tensions resulted in the confiscation of German ships interned in Portuguese ports, to which Germany reacted by declaring war on 9 March 1916, quickly followed by Portugal's reciprocal declaration.
Coastal defence ships were warships built for the purpose of coastal defence, mostly during the period from 1860 to 1920. They were small, often cruiser-sized warships that sacrificed speed and range for armour and armament. They were usually attractive to nations that either could not afford full-sized battleships or could be satisfied by specially designed shallow-draft vessels capable of littoral operations close to their own shores. The Nordic countries and Thailand found them particularly appropriate for their island-dotted coastal waters. Some vessels had limited blue-water capabilities; others operated in rivers.
World War I or the First World War, often abbreviated as WWI or WW1, and referred to by some Anglophone authors as the "Great War" or the "War to End All Wars", was a global conflict which lasted from 1914 to 1918, and is considered one of the deadliest conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war.
SS Maverick was an oil tanker built in 1890 for the Standard Oil of New York, later Mobil Oil. After the ship had changed hands sometime between 1910 and 1915, it was used during World War I as part of the Hindu–German Conspiracy to foment rebellion in India and overthrow the British Raj. According to one source, the ship sank in 1917.
SM UB-46 was a Type UB II submarine or U-boat for the German Imperial Navy during World War I. UB-46 operated in the Mediterranean and the Black Seas, and was sunk by a mine in December 1916.
SM U-4 or U-IV was a U-3-class submarine or U-boat built for and operated by the Austro-Hungarian Navy before and during the First World War. The submarine was built as part of a plan to evaluate foreign submarine designs, and was the second of two boats of the class built by Germaniawerft of Kiel, Germany.
The Type U 66 was a class of five submarines or U-boats operated by the German Imperial Navy during World War I. The class is alternately referred to as the U-66-class or the Type UD. The class was built by Germaniawerft of Kiel to their 506d design as the U-7-class for the Austro-Hungarian Navy. The five boats were sold to the Imperial Germany Navy at the beginning of World War I when it was thought impossible for the submarines to reach the Mediterranean for delivery to Austria-Hungary.
SM U-15 or U-XV was a U-10-class submarine or U-boat of the Austro-Hungarian Navy during World War I. U-15 was constructed in Germany and shipped by rail to Pola where she was assembled and launched in April 1915. She was commissioned in October 1915. U-15 was the most successful boat of the U-10 class, sinking six ships totaling 8,044 gross register tons (GRT) and 745 tons. The boat survived the war and was handed over to Italy as a war reparation and scrapped in 1920.
The U-27 class was a class of eight submarines or U-boats built for and operated by the Austro-Hungarian Navy during World War I. The class was based upon the German Type UB II design of the German Imperial Navy and was constructed under license in Austria-Hungary.
The U-43 class was a class of two coastal submarines or U-boats operated by the Austro-Hungarian Navy during World War I. The two submarines that comprised the class were Type UB II submarines of the Imperial German Navy, making the two classes identical. From the beginning of World War I, Austria-Hungary had been working to increase the size of its U-boat fleet, so the Imperial German Navy, which was finding it difficult to obtain trained submarine crews, sold two of its UB II boats, UB-43 and UB-47, to its ally in June 1917.
SM U-66 was the lead ship of the Type U-66 submarines or U-boats for the Imperial German Navy during World War I. The submarine had been laid down in Kiel in November 1913 as U-7, the lead ship of the U-7 class for the Austro-Hungarian Navy. They became convinced after the outbreak of war in August 1914 that none of these submarines could be delivered to the Adriatic via Gibraltar, and sold the entire class, including U-7, to the German Imperial Navy in November 1914.
SM U-27 or U-XXVII was the lead boat of the U-27 class of U-boats or submarines for the Austro-Hungarian Navy. U-27 was built by the Austrian firm of Cantiere Navale Triestino (CNT) at the Pola Navy Yard and launched on 19 October 1916. She was commissioned on 24 February 1917.
SS Galeka was a steam ship built in 1899 for the Union-Castle Mail Steamship Company by Harland and Wolff. She was launched on 21 October 1899 and completed on 23 December 1899. Later she was requisitioned for use as a British troop transport and then a hospital ship during the First World War. On 28 October 1916 she struck a mine laid by the German U-boat UC-26.
The Jubilee class were a group of five passenger and cargo ocean liners built by Harland and Wolff at Belfast, for the White Star Line, specifically for the White Star Line's service from the UK to Australia on the Liverpool–Cape Town–Sydney route. The five ships in order of the dates they entered service were:
United Kingdom 
