Question: The 26th Battalion was an infantry battalion of the Australian Army, the battalion fought at Gallipoli in the latter stages of that campaign, what is the title of the campaign of the First World War that took place on the Gallipoli peninsula (Gelibolu in modern Turkey) in the Ottoman Empire between 25 April 1915 and 9 January 1916?
Context: The 25th Battalion was an infantry unit of the Australian Army.  Raised in early 1915 as part of the Australian Imperial Force during the First World War, the battalion fought at Gallipoli and in the trenches along the Western Front, before being disbanded in early 1919.  In mid-1921, it was re-formed as a part-time unit based in the state of Queensland.  Throughout the 1930s, the battalion was merged briefly with the 49th Battalion as a result of manpower shortages, but was later re-raised in its own right.  During the Second World War, the 25th deployed to New Guinea where they fought the Battle of Milne Bay in August and September 1942.  Later in the war, the 25th took part in the Bougainville Campaign.  During the post-war period, the 25th Battalion became part of the Royal Queensland Regiment, variously forming battalion or company-sized elements, before being merged with the 49th Battalion to form the 25th/49th Battalion, Royal Queensland Regiment. The 5th Battalion was an infantry battalion of the Australian Army.  Raised in Victoria as part of the First Australian Imperial Force for service during World War I, the battalion formed part of the 2nd Brigade, attached to the 1st Division.  It participated in the landing at Anzac Cove on 25 April 1915, coming ashore in the second wave, before taking part in the fighting at Krithia and then at Lone Pine.  In December 1915 the battalion was withdrawn from the peninsula and returned to Egypt where it was involved in defending the Suez Canal until being transferred to the Western Front in France in early 1916.  After that, over the course of the next two and a half years the 5th Battalion was rotated in and out of the front line and took part in a number of significant battles including at Pozieres, Ypres, Amiens and the Hindenburg Line.  Following the end of the war, the battalion was disbanded and its personnel returned to Australia.  The battalion was re-raised during the inter-war years as a part-time unit and was later mobilised during World War II, but did not serve overseas.  During the post war period, the battalion has existed at various times before being subsumed into the 5th/6th Battalion, Royal Victoria Regiment. The 26th Battalion was an infantry battalion of the Australian Army.  Originally raised in April 1915 for service in World War I as part of the Australian Imperial Force (AIF), it was assigned to the 7th Brigade and consisted of personnel recruited from the states of Queensland and Tasmania.  The battalion fought at Gallipoli in the latter stages of that campaign before being withdrawn to Egypt in late 1915.  In mid-1916, it was sent to Europe where it served in the trenches of the Western Front in France and Belgium for the rest of the war, fighting in most of the battles that the Australians took part in between 1916 and 1918.  At the end of the war it was disbanded in May 1919 as part of the demobilisation of the AIF. The 19th Battalion was an infantry battalion of the Australian Army.  Although the unit's numerical designation was bestowed upon it during World War I, the unit can trace its origins back to 1860 when a Volunteer Rifle corps was raised in South Sydney.  During World War I, the 19th Battalion was raised as a unit of the Australian Imperial Force, attached to the 5th Brigade, of the 2nd Division.  The unit was formed in 1915 and was first sent to Gallipoli where it fought against the Turks, before being withdrawn from the peninsula and being sent to France in early 1916, where it served in the trenches along the Western Front.  Over the next two years the battalion fought in many major battles and won numerous battle honours.  In April 1918, it took part in defending against the German Spring Offensive, before the Allies launched their own last-ditch effort as part of the Hundred Days Offensive.  The battalion was disbanded in October 1918 due to manpower shortages in the AIF and most of its men were sent to reinforce the other three battalions of the 5th Brigade. The 10th Battalion was an infantry battalion of the Australian Army that served as part of the Australian Imperial Force during World War I. Among the first units raised in Australia during the war, the battalion was recruited from South Australia in August 1914 and along with the 9th, 11th and 12th Battalions, it formed part of the 3rd Brigade, 1st Division.  After its personnel completed basic training, the battalion embarked for the Middle East, where further training was undertaken in Egypt before the battalion was committed to the Gallipoli Campaign.  On 25 April 1915, the 10th Battalion took part in the Landing at Anzac Cove, coming ashore during the initial stages of the operation as part of the covering force.  Members from the 10th Battalion penetrated the furthest inland of any Australian troops during the initial fighting, before the Allied advance inland was checked.  After this, the battalion helped defend the beachhead against a Turkish counter-attack in May, before joining the August Offensive, a failed Allied effort to break the deadlock.  Casualties were heavy throughout the campaign and in November 1915, the surviving members were withdrawn from the peninsula and in early 1916 the battalion was reformed in Egypt.  After a period of reorganisation, during which the 10th provided a cadre staff to the newly formed 50th Battalion, it was transferred to the Western Front in March 1916, and for the next two-and-a-half years took part in trench warfare in France and Belgium until the Armistice in 1918.  The last detachment of men from the 10th Battalion returned to Australia in September 1919. The 22nd Battalion was an infantry battalion of the Australian Army.  It was raised in 1915 as part of the Australian Imperial Force for service during World War I and formed part of the 6th Brigade, attached to the 2nd Division.  It fought during the Gallipoli campaign and on the Western Front before being disbanded in 1919.  In 1921, it was re-raised as a part-time unit and was merged with the 29th Battalion in 1930 to form the "29th/22nd Infantry Battalion".  Split in August 1939 and known as the "22nd Battalion (South Gippsland Regiment)", the battalion saw action against the Japanese during World War II in the Huon Peninsula and New Britain campaigns.  The battalion was disbanded in June 1946.  It was re-established as part of the Royal Victoria Regiment in the mid-1960s as a remote area battalion within the Citizens Military Force, and later became a part of the 8th/7th Battalion, Royal Victoria Regiment. The 28th Battalion was an infantry battalion of the Australian Army.  It was raised in early 1915 as part of the First Australian Imperial Force for service during the First World War and formed part of the 7th Brigade, attached to the 2nd Division.  It fought during the final stages of the Gallipoli campaign in late 1915 and then on the Western Front between 1916 and 1918.  At the end of the war, the 28th was disbanded in 1919 but was re-raised in 1921, as a part-time unit based in Western Australia.  During the Second World War, the 28th undertook defensive duties in Australia for the majority of the conflict, before seeing action against the Japanese in the New Britain campaign in 1944–45.  The battalion was disbanded in March 1946 but was re-formed in 1948 as an amalgamated unit with the 16th Battalion, before being unlinked in 1952 and re-raised as a full battalion following the reintroduction of national service.  It remained on the Australian Army's order of battle until 1960 when it was subsumed into the Royal Western Australia Regiment, but was later re-raised in 1966 as a remote area infantry battalion.  In 1977, the 28th was reduced to an independent rifle company, and in 1987 was amalgamated into the 11th/28th Battalion, Royal Western Australia Regiment. The 11th Battalion was an Australian Army battalion that was among the first infantry units raised during World War I for the First Australian Imperial Force.  It was the first battalion recruited in Western Australia, and following a brief training period in Perth, the battalion sailed to Egypt where it undertook four months of intensive training.  In April 1915 it took part in the invasion of the Gallipoli Peninsula, landing at Anzac Cove.  In August 1915 the battalion was in action in the Battle of Lone Pine.  Following the withdrawal from Gallipoli, the battalion returned to Egypt where it was split to help form the 51st Battalion.  In March 1916, the battalion was deployed to the Western Front in France and Belgium where it took part in trench warfare until the end of the war in November 1918. The Gallipoli Campaign, also known as the Dardanelles Campaign, the Battle of Gallipoli, or the Battle of Çanakkale (Turkish: "Çanakkale Savaşı" ), was a campaign of the First World War that took place on the Gallipoli peninsula (Gelibolu in modern Turkey) in the Ottoman Empire between 25 April 1915 and 9 January 1916.  The peninsula forms the northern bank of the Dardanelles, a strait that provided a sea route to the Russian Empire, one of the Allied powers during the war.  Intending to secure it, Russia's allies, Britain and France, launched a naval attack followed by an amphibious landing on the peninsula, with the aim of capturing the Ottoman capital of Constantinople (modern Istanbul).  The naval attack was repelled and after eight months' fighting, with many casualties on both sides, the land campaign was abandoned and the invasion force was withdrawn to Egypt. The 15th Battalion was an infantry battalion of the Australian Army.  Formed in 1914 as part of the all-volunteer Australian Imperial Force from Queensland and Tasmanian recruits, the battalion fought during the Gallipoli Campaign and on the Western Front during the First World War.  It was disbanded after the war in 1919, but later re-raised as a part-time Citizens Forces unit based in Queensland in 1921, consisting of a mixture of volunteers and conscripts.  Economic pressures and limited manpower resulted in the battalion being amalgamated with other battalions a couple of times during the inter-war years.  In mid-1939, as rising tensions in Europe led to an expansion of the Australian military, the battalion was re-formed in its own right.  During the Second World War the 15th Battalion was mobilised for wartime service and initially undertook defensive duties in Australia before taking part in the fighting against the Japanese in New Guinea and Bougainville in 1943–1945.  The battalion was disbanded in 1946 and never re-raised.
Answer: Gallipoli Campaign