Question: Which battle, Operation Grenade or the Battle of Fredericksburg, occurred first?
Context: A grenadier (from French, derived from the word grenade) was originally a specialized soldier, first established as a distinct role in the mid-to-late 17th century, for the throwing of grenades and sometimes assault operations.  At that time grenadiers were chosen from the strongest and largest soldiers.  By the 18th century, dedicated grenade throwing of this sort was no longer relevant, but grenadiers were still chosen for being the most physically powerful soldiers and would lead assaults in the field of battle.  Grenadiers would also often lead the storming of fortification breaches in siege warfare, although this role was more usually fulfilled by all-arm units of volunteers called forlorn hopes, and might also be fulfilled by sappers or pioneers. Thomas "Tom" Fosmire joined the Central Intelligence Agency's Special Operations Group in the 1950s and was given responsibility (along with Tony Poe) in training Tibetan tribesmen to fight against the Chinese Communists in the early part of his career.  The training occurred first at a base on Saipan in the Marianas islands but was later moved to a colder mountainous climate at Camp Hale, Colorado.  One battalion was trained at Camp Peary, near Williamsburg, Virginia.  After the Tibetan operation concluded, Fosmire landed with Tony Poe in Sumatra, Indonesia to supply and train mutinous forces there in an effort by the Eisenhower administration to destabilize the communist-leaning regime of Sukarno.  He and Poe were evacuated from Sumatra by US Navy submarine when the troops they were training fled to the mountains.  In the 1980s, Fosmire served in El Salvador and Honduras, training Nicaraguan rebel troops opposed to the Sandanista government. During World War II, Operation Grenade was the crossing of the Roer (Rur) river between Roermond and Düren by the U.S. Ninth Army, commanded by Lieutenant General William Hood Simpson, in February 1945. The Battle of Gang Toi (8 November 1965) was fought during the Vietnam War between Australian troops and the Viet Cong.  The battle was one of the first engagements between the two forces during the war and occurred when A Company, 1st Battalion, Royal Australian Regiment (1 RAR) struck a Viet Cong bunker system defended by Company 238 in the Gang Toi Hills, in northern Bien Hoa Province.  It occurred during a major joint US-Australian operation codenamed Operation Hump, involving the US 173rd Airborne Brigade, to which 1 RAR was attached.  During the latter part of the operation an Australian rifle company clashed with an entrenched company-sized Viet Cong force in well-prepared defensive positions.  Meanwhile, an American paratroop battalion was also heavily engaged in fighting on the other side of the Song Dong Nai. William Farrar Smith (February 17, 1824 – February 28, 1903), known as ‘Baldy’ Smith, was a Union general in the American Civil War, notable for attracting the extremes of glory and blame.  He was praised for his gallantry in the Seven Days Battles and the Battle of Antietam, but was demoted for insubordination after the disastrous defeat at the Battle of Fredericksburg.  As chief engineer of the Army of the Cumberland, he achieved recognition by restoring a supply line that saved that army from starvation and surrender, known the “Cracker Line”, that helped Union troops to success in the Chattanooga Campaign in the autumn of 1863.  Leading the first operation against Petersburg, Smith’s hesitation, possibly illness-related, cost the Union a prime opportunity for a quick end to the war, and he was relieved of command. The Battle of Norfolk was a tank battle fought on February 27, 1991, during the Persian Gulf War, between armored forces of the United States and United Kingdom, and those of the Ba'athist Iraqi Republican Guard.  The primary participants were the U.S. 2nd Armored Division (Forward),1st Infantry Division (Mechanized), and the Iraqi 18th Mechanized and 9th Armoured Brigades of the Republican Guard Tawakalna Mechanized Infantry Division along with elements from eleven other Iraqi divisions.  The 2nd Armored Division(Fwd) was assigned to the American 1st Infantry Division as its 3rd maneuver brigade due to the fact that one of its brigades was not deployed.  The British 1st Armoured division was responsible for protecting the right flank of VII Corps.  Its main adversary being the Iraqi 52nd Armored Division and multiple infantry divisions.  It was the final battle of the war before the unilateral ceasefire took effect.  Two more battles occurred at Objective Dorset and near the oil field at Rumaila after the ceasefire.  The Battle of Norfolk has been recognized by some sources as the second largest tank battle in American history and the largest tank battle of the 1st Gulf War.  No fewer than 12 divisions participated in the Battle of Norfolk along with multiple brigades and elements of a regiment.  American and British forces destroyed approximately 750 Iraqi tanks and hundreds of other types of combat vehicles.  This goes without even taking into consideration the destruction of two additional Republican Guard divisions at Objective Dorset by the 3rd Armored Division on 28 February 1991.  During this action the 3rd Armored Division destroyed 250 enemy vehicles and captured 2,500 Iraqi soldiers.  Over a decade passed after the conflict before quality references became available on most of the battles that took place during the 1st Gulf War.  Many of the land battles during Operation Desert Storm were larger than the majority of the battles that took place in southern and western Europe during World War Two, at least as far as the quantity of equipment involved. Chancellorsville is a historic site and unincorporated community in Spotsylvania County, Virginia, about ten miles west of Fredericksburg.  The name of the locale derives from the mid-19th century inn operated by the family of George Chancellor at the intersection of the Orange Turnpike and Orange Plank Road.  The American Civil War Battle of Chancellorsville occurred there in May 1863, and the Battle of the Wilderness was fought nearby in May 1864.  During the 1863 battle, Lt. Gen. Thomas J. "Stonewall" Jackson was wounded by friendly fire, dying eight days later on May 10, 1863, from pneumonia. The Battle of Fredericksburg was fought December 11–15, 1862, in and around Fredericksburg, Virginia, between General Robert E. Lee's Confederate Army of Northern Virginia and the Union Army of the Potomac, commanded by Major General Ambrose Burnside, as part of the American Civil War.  The Union Army's futile frontal attacks on December 13 against entrenched Confederate defenders on the heights behind the city are remembered as one of the most one-sided battles of the war, with Union casualties more than three times as heavy as those suffered by the Confederates.  A visitor to the battlefield described the battle to U.S. President Abraham Lincoln as a "butchery." The attack occurred on a Friday morning.  ETA had observed similar convoys from the factory and planned their ambush based on information that they had gathered.  The convoy consisted of four vehicles, the first carrying technicians, the third mortar devices produced by the factory and the second and fourth vehicles carrying three civil guards each.  The vehicle left the factory at 0730 and at approximately 0815, had to slow down at a part of the road which consisted of numerous bends.  The ETA members had chosen a spot near a small hill, where they were hidden from view by dense vegetation.  After allowing the vehicle carrying the factory workers to pass, ETA launched a grenade at the second vehicle, causing it to be stuck in a layby and then attacked the civil guard's vehicles with assault rifles, machine guns and grenades, firing over 100 shots.  In order to ensure that no civil guards survived, the ETA members approached the vehicles and threw a hand grenade into the first civil guard's vehicle.  When they repeated this with the second vehicle, two ETA members, Gregorio Olabarría Gorrotxategui Bengoa and Javier Argote, were killed as a result of injuries suffered when they failed to escape in time before the grenades exploded.  One of these was subsequently found 6 kilometres away from the attack, having apparently been moved there by his comrades.  At 0845, a man had approached a bar near the scene and had asked in Basque for medical assistance. The Battle of Prek Klok II occurred on March 10, 1967, during Operation Junction City when American military forces were conducting a search and destroy operation against the Viet Cong forces in Tay Ninh Province west of the capital of South Vietnam, Saigon.  During the course of the operation they had already had a significant engagement in the Battle of Prek Klok I.  During the night, Artillery Fire Support Patrol Base II at Prek Klok was attacked by two communist battalions, resulting in a short battle.  This was the second major battle of Operation Junction City.  The communists started by mortaring the base and launching anti-tank fire at the armored personnel carriers (APCs) surrounding the base.  Attacks came from the north and east, followed by an infantry charge out of wooded areas from the southwest.  With the help of air strikes from nearby planes, as well as artillery and ample supplies flown in by helicopter, the Americans easily repelled the communist attack, which consisted of two battalions.  The Americans killed 197 communists but lost only three of their men.
Answer: Battle of Fredericksburg