Question: What year was George Sellars fatally wounded at the Battle of Messines in West Flanders, Belgium?

full_context: Document 1: George Sellars: George Maurice Victor Sellars (16 April 18867 June 1917) was a rugby union player who represented New Zealand fifteen times, including two Test matches. He played club rugby for Ponsonby, and was first selected for Auckland in 1910, and in 1912 gained international selection for New Zealand Māori. Sellars was selected for the All Blacksas New Zealand's international team is knownfor their 1913 tour of North America where he played fourteen matches. As well, he was also in the All Blacks' side that played Australia immediately prior to their tour. Although unavailable to play for New Zealand the following year, he did represent the Māori again that season. In 1915 Sellars enlisted for service in the First War War, and he was fatally wounded in 1917 at the Battle of Messines.
Document 2: Mines in the Battle of Messines (1917): The mines in the Battle of Messines comprised a series of underground explosive charges, secretly planted by British tunnelling units beneath the German 4th Army lines near the village of Mesen ("Messines" in French, historically used in English) in Belgian West Flanders during the First World War. The mines were detonated at the start of the Battle of Messines (7–14 June 1917) , creating 19 large craters. The joint explosion of the mines at Messines ranks among the largest non-nuclear explosions of all time. The evening before the attack, General Sir Charles Harington, Chief of Staff of the Second Army (General Sir Herbert Plumer), remarked to the press, "Gentlemen, we may not make history tomorrow, but we shall certainly change the geography". The Battle of Messines marked the zenith of mine warfare. On 10 August 1917, the Royal Engineers fired the last British deep mine of the war, at Givenchy-en-Gohelle near Arras.
Document 3: Lewis Allen (rugby union): Lewis Allen (30 October 1870 – 17 October 1932) was a New Zealand rugby union player. A centre and five-eighth, Allen represented Taranaki and, briefly, Manawatu at a provincial level. He was a member of the New Zealand national side between 1896 and 1901, appearing in 13 matches, but no test matches as New Zealand did not play its first full international until 1903. Lewis died in Nelson in 1932, and was buried at Wakapuaka Cemetery.
Document 4: Battle of the Frontiers: The Battle of the Frontiers was a series of battles fought along the eastern frontier of France and in southern Belgium shortly after the outbreak of World War I. The battles resolved the military strategies of the French Chief of Staff General Joseph Joffre with Plan XVII and an offensive interpretation of the German "Aufmarsch II" deployment plan by Helmuth von Moltke the Younger. The German concentration on the right (northern) flank, to wheel through Belgium and attack the French in the rear, was delayed by the movement of General Charles Lanrezac's Fifth Army towards the north-west to intercept them and the presence of the British Expeditionary Force (BEF) on his left flank. The Franco-British were driven back by the Germans, who were able to invade northern France. French and British rearguard actions delayed the German advance, allowing the French time to transfer their forces to the west to defend Paris, resulting in the First Battle of the Marne.
Document 5: Battle of Arras (1917): The Battle of Arras (also known as the Second Battle of Arras) was a British offensive on the Western Front during World War I. From 9 April to 16 May 1917, British troops attacked German defences near the French city of Arras on the Western Front. The British achieved the longest advance since trench warfare had begun, surpassing the record set by the French Sixth Army on 1 July 1916. The British advance slowed in the next few days and the German defence recovered. The battle became a costly stalemate for both sides and by the end of the battle the British Third and First armies had suffered about 160,000 casualties and the German 6th Army 125,000 casualties.
Document 6: Battle of the Hills: The Battle of the Hills (French: "Bataille des Monts" ) also known as the Battle of the Hills of Champagne and the Third Battle of Champagne, was a battle of the First World War that was fought from April–May 1917. The French Fourth Army offensive against the German 4th Army was intended to be auxiliary to that of the "Groupe d'armées du Nord" (GAN, Northern Army Group) along the Chemin des Dames, in the Second Battle of the Aisne. General Anthoine, commander of the Fourth Army planned a supporting attack but this was rejected by Nivelle and Anthoine planned a frontal attack by two corps on an 11 km front, to break through the German defences on the first day and commence exploitation the following day. The battle took place east of Reims, between Prunay and Aubérive, in the province of Champagne, along the Moronvilliers Hills.
Document 7: Nivelle Offensive: The Nivelle Offensive of 1917, was a Franco-British offensive on the Western Front in the First World War. The French part of the offensive was intended to be strategically decisive, by breaking through the German defences on the Aisne front within 48 hours, with casualties expected to be around 10,000 men. A preliminary attack was to be made by the French Third Army at St. Quentin and the British First, Third and Fifth armies at Arras, to capture high ground and divert German reserves from the French fronts on the Aisne and in Champagne. The main offensive was to be delivered by the French on the Chemin des Dames ridge (the Second Battle of the Aisne, "La bataille du Chemin des Dames" , "Seconde bataille de l'Aisne" and "Doppelschlacht Aisne-Champagne" ), with a subsidiary attack by the Fourth Army (the Third Battle of Champagne, the Battle of the Hills or Battle of the Hills of Champagne). The final stage of the offensive was to follow the meeting of the British and French armies, having broken through the German lines, with a pursuit of the defeated German armies towards the German frontier.
Document 8: Messines Ridge (New Zealand) Memorial: The Messines Ridge (New Zealand) Memorial is a World War I memorial, located in Messines Ridge British Cemetery, near the town of Mesen, Belgium. The memorial lists 827 officers and men of the New Zealand Expeditionary Force with no known grave who died in or near Messines in 1917 and 1918. This period included the Battle of Messines.
Document 9: George Thomas (rugby): George W. 'Ponty' Thomas (1881 – 3 July 1916) was a Welsh rugby union and professional rugby league footballer who played in the 1900s, and 1910s, playing club rugby union (RU) for Pontnewydd RFC, and Newport RFC, and playing representative level rugby league (RL) for Great Britain, Wales, Other Nationalities, and Lancashire, and at club level for Warrington (Heritage № 111), as a prop , or second-row , i.e. number 8 or 10, or, 11 or 12, during the era of contested scrums. Born in Pontnewydd, Wales, he died at the Somme on 3 July 1916 while serving with the South Lancashire Regiment of the British Army; he was 35 years old.
Document 10: Hal Sever: Hal Sever (c. 1910 – June 2005) was an English rugby international playing ten matches. He was educated at Shrewsbury School, which is normally regarded as a footballing school. He made his debut in 1936 as a member of the first English team to defeat the All Blacks and played an integral role in the English team in 1937 that won the Triple Crown. He played his last international game against Scotland in 1938. He played club rugby for Sale and represented Cheshire as well as playing 8 matches for the Barbarians.
Document 11: Battle of Vimy Ridge: The Battle of Vimy Ridge was a military engagement fought primarily as part of the Battle of Arras, in the Nord-Pas-de-Calais region of France, during the First World War. The main combatants were the Canadian Corps, of four divisions, against three divisions of the German Sixth Army. The battle, which took place from 9 to 12 April 1917, was part of the opening phase of the British-led Battle of Arras, a diversionary attack for the French Nivelle Offensive.
Document 12: George Nicholson (rugby player): George Nicholson (3 August 187813 September 1968) was a New Zealand rugby union footballer who played for New Zealandthe "All Blacks"between 1903 and 1907. He played club rugby in Auckland for the City club, before making his provincial debut for Auckland in 1901. After playing for the North Island in 1902, he was selected for New Zealand's tour of Australia in 1903 where he played in the All Blacks' first ever Test matchagainst Australia in Sydney. The following year he was selected for New Zealand when they played a one-off Test against the British Isles who were touring New Zealand; New Zealand's first home international. In 1905 and 1906 he was selected for the All Blacks tour of Europe and North America. This was the first New Zealand national team to tour the Northern Hemisphere, and played 20 matches during the trip, but did not appear in any internationals. After returning to New Zealand he switched clubs to Ponsonby in 1907, and that year played two Tests for New Zealand against Australiahis last matches representing his country. After retiring from rugby he was involved in the sport as a referee, selector and administrator. He was one of the last surviving members of the "Original All Blacks", as the 1905 team was called, and was present at the 75th jubilee celebrating for the formation of the New Zealand Rugby Football Union in 1967.
Document 13: Battle of Messines (1917): The Battle of Messines (7–14 June 1917) was conducted by the British Second Army (General Sir Herbert Plumer), on the Western Front near the village of Messines in West Flanders, Belgium, during the First World War. The Nivelle Offensive in April and May had failed to achieve its more ambitious aims, had led to the demoralisation of French troops and dislocated the Anglo-French strategy for 1917. The offensive at Messines forced the Germans to move reserves to Flanders from the Arras and Aisne fronts, which relieved pressure on the French. The tactical objective of the attack at Messines was to capture the German defences on the ridge, which ran from Ploegsteert (Plugstreet) Wood in the south, through Messines and Wytschaete to Mt. Sorrel, to deprive the German 4th Army of the high ground south of Ypres. The ridge commanded the British defences and back areas further north, from which the British intended to conduct the Northern Operation, an advance to Passchendaele Ridge and then capture the Belgian coast up to the Dutch frontier.
Document 14: Gary Seear: Gary Alan Seear (born 19 February 1952) is a former New Zealand rugby union player. A number eight later in his career, Seear made his debut for Otago as a 19-year-old as a lock. He captained the 1974 Junior All Blacks. Seear toured South Africa with the 1976 All Blacks but did not make an appearance until the following year where he played at number eight in two tests in France. He made further appearances in the 1978 home series against the Wallabies, the 1979 French tourists side, four more internationals in Britain and the sole test in Australia in 1979. He played in Italy for the Fracasso San Dona club during the 1979 season. He now works as a commercial property sales consultant for worldwide real estate firm Colliers International in Christchurch.
Document 15: George Davies (rugby player): George Davies (25 December 1875–23 July 1959) was a Welsh international rugby union forward who played club rugby for Llandeilo and Swansea. A two time Triple Crown winner, Davies would represent his country on nine occasions. A skillful player, Davies was unfortunate to be playing during the same period as Rhys Gabe, who was the selectors' first choice at his position. It was all the more unfortunate for Davies as it was a collision between himself and Gabe, during a Swansea match, that caused an injury that would allow Gabe to take his position for Wales.
ground_truth: 1917