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.
The Second Battle of Guam (21 July – 10 August 1944) was the American recapture of the Japanese-held island of Guam, a U.S. territory in the Mariana Islands captured by the Japanese from the U.S. in the 1941 First Battle of Guam during the Pacific campaign of World War II.
The Battle of Verdun ("Bataille de Verdun", ] , "Schlacht um Verdun", ] ), fought from 21 February to 18 December 1916, was the largest and longest battle of the First World War on the Western Front between the German and French armies.
 The battle took place on the hills north of Verdun-sur-Meuse in north-east France.
 The German 5th Army attacked the defences of the Fortified Region of Verdun ("RFV, Région Fortifiée de Verdun") and those of the French Second Army on the right bank of the Meuse.
 Inspired by the experience of the Second Battle of Champagne in 1915, the Germans planned rapidly to capture the Meuse Heights, an excellent defensive position with good observation for the artillery to bombard Verdun.
 The Germans hoped that the French would commit their strategic reserve to recapture the position and suffer catastrophic losses in a battle of annihilation, not costly for the Germans because of their tactical advantage.
The Second Battle of the Marne (French: "Seconde Bataille de la Marne" ), or "Battle of Reims" (15 July – 6 August 1918) was the last major German offensive on the Western Front during the First World War.
 The attack failed when an Allied counterattack by French and American forces, including several hundred tanks, overwhelmed the Germans on their right flank, inflicting severe casualties.
 The German defeat marked the start of the relentless Allied advance which culminated in the Armistice with Germany about 100 days later.
The Marne Medal (French - "médaille de la Marne") was a French medal awarded to soldiers who had fought in the First Battle of the Marne, the Second Battle of the Marne or both engagements, particularly those who took part in fighting between 6 and 12 September 1914 on the Senlis front at Verdun.
The Battle of Cambrai, 1918 (also known as the Second Battle of Cambrai) was a battle between troops of the British First, Third and Fourth Armies and German Empire forces during the Hundred Days Offensive of the First World War.
 The battle took place in and around the French city of Cambrai, between 8 and 10 October 1918.
 The battle incorporated many of the newer tactics of 1918, in particular tanks.
 The attack was an overwhelming success with light casualties in an extremely short amount of time.
The Battle of Cape Esperance, also known as the Second Battle of Savo Island and, in Japanese sources, as the Sea Battle of Savo Island (サボ島沖海戦 ) , took place on 11–12 October 1942 in the Pacific campaign of World War II between the Imperial Japanese Navy and United States Navy.
 The naval battle was the second of four major surface engagements during the Guadalcanal campaign and took place at the entrance to the strait between Savo Island and Guadalcanal in the Solomon Islands.
 Cape Esperance ( ) is the northernmost point on Guadalcanal, and the battle took its name from this point.
The Second Battle of Passchendaele was the culminating attack during the Third Battle of Ypres of the First World War.
 The battle took place in the Ypres Salient area of the Western Front, in and around the Belgian village of Passchendaele, between 26 October and 10 November 1917.
 The Canadian Corps relieved the exhausted II Anzac Corps, continuing the advance started with the First Battle of Passchendaele and ultimately capturing the village.
 Beyond gaining favourable observation positions, the battle was intended to gain drier winter positions on higher ground.
The First Battle of Guam was an engagement during the Pacific War in World War II, and took place from 8 December to 10 December 1941 on Guam in the Mariana Islands between Japan and the United States.
 The American garrison was defeated by Japanese forces on 10 December, which resulted in an occupation until the Second Battle of Guam in 1944.
The Battle of the Allia was fought between the Senones (one of the Gallic tribes which had invaded northern Italy) and the Romans.
 It was fought at the confluence of the rivers Tiber and Allia, eleven Roman miles (16 km) north of Rome.
 The Romans were routed and subsequently the Senones sacked Rome.
 The common date given for the battle is 390 BC.
 This is based on the account of the battle by the Roman historian Livy and the Varronian Chronology, a Roman dating system.
 The ancient Greek historian Polybius, who used a Greek dating system, derived the date 387/6 BC.
 Plutarch wrote that the battle took place just after the summer solstice when the moon was near the full, a little more than three hundred and sixty years from the foundation of Rome.
 That would be shortly after 393 BC.
 Tacitus said that the battle took place the 15 before the Kalends of August, which is 18 July.

Question: Which battle took place first, Second Battle of the Marne or Battle of Guam?
Answer: The Second Battle of the Marne