Question: The War of the Roses is partly adapted from a Shakespeare play that culminates in which opening battle of the war?

Context paragraphs:
List of Excel Saga chapters: This is a list of the chapters and volumes of the seinen manga series "Excel Saga" by Rikdo Koshi.  The chapters began serialization in "Young King Ours" in September 1996, and ended in 2011.  The individual chapters are collected and published in 27 tankōbon volumes by Shōnen Gahosha between April 1997 and October 2011.  The manga was partly adapted into a twenty-six episode anime by J.C.Staff which aired on TV Tokyo in Japan from October 7, 1999 to March 30, 2000.

Battle of Selinus: The Battle of Selinus, which took place early in 409 BC, is the opening battle of the so-called Second Sicilian War.  The 10-day-long siege and battle was fought in Sicily between the Carthaginian forces under Hannibal Mago (A king of Carthage of the Magonid family, not the famous Hannibal of the Barcid family) and the Dorian Greeks of Selinus.  The city of Selinus had defeated the Elymian city of Segesta in 415 BC, an event that led to the Athenian invasion of Sicily in 415 BC and ended in the defeat of Athenian forces in 413 BC.  When Selinus again worsted Segesta in 411 BC, Carthage, responding to the appeal of Segesta, had besieged and sacked Selinus after the Carthaginian offer of negotiations had been refused by the Greeks.  This was the first step towards Hannibal's campaign to avenge the Carthaginian defeat at the 1st battle of Himera in 480 BC.  The city of Selinus was later rebuilt, but never regained her former status.

Battle of Ali Masjid: The Battle of Ali Masjid, which took place on 21 November 1878, was the opening battle in the Second Anglo-Afghan War between the British forces, under Lieutenant-General Sir Samuel James Browne, and the Afghan forces, under Ghulam Haider Khan.  The perceived offence of an Afghan general's refusal to allow a British envoy entrance to the country was used as an excuse to attack the fortress of Ali Masjid, as the opening battle in the war.  Despite numerous setbacks, including half the troops getting lost or delayed and missing the battle entirely, the British were lucky that the Afghans abandoned their position overnight.

The Wars of the Roses (adaptation): The Wars of the Roses was a 1963 theatrical adaptation of William Shakespeare's first historical tetralogy ("1 Henry VI", "2 Henry VI", "3 Henry VI" and "Richard III"), which deals with the conflict between the House of Lancaster and the House of York over the throne of England, a conflict known as the Wars of the Roses.  The plays were adapted by John Barton, and directed by Barton himself and Peter Hall at the Royal Shakespeare Theatre.  The production starred David Warner as Henry VI, Peggy Ashcroft as Margaret of Anjou, Donald Sinden as the Duke of York, Paul Hardwick as the Duke of Gloucester, Janet Suzman as Joan la Pucelle, Brewster Mason as the Earl of Warwick, Roy Dotrice as Edward IV, Susan Engel as Queen Elizabeth and Ian Holm as Richard III.

Battle of Lushunkou: The Battle of Lüshunkou (; Japanese: "Ryōjunkō-no-tatakai" (旅順口の戦い ) ) was a land battle of the First Sino-Japanese War.  It took place on 21 November 1894 in Lüshunkou, Manchuria (later called Port Arthur, in present-day Liaoning Province, China) between the forces of the Empire of Japan and the Empire of China.  It is sometimes referred to archaically in western sources as the Battle of Port Arthur (that name is now primarily used for the opening battle of the Russo-Japanese War in 1904).

Abner Doubleday: Abner Doubleday (June 26, 1819January 26, 1893) was a career United States Army officer and Union general in the American Civil War.  He fired the first shot in defense of Fort Sumter, the opening battle of the war, and had a pivotal role in the early fighting at the Battle of Gettysburg.  Gettysburg was his finest hour, but his relief by Maj. Gen. George G. Meade caused lasting enmity between the two men.  In San Francisco, after the war, he obtained a patent on the cable car railway that still runs there.  In his final years in New Jersey, he was a prominent member and later president of the Theosophical Society.  Doubleday has been historically credited with inventing baseball, although this is untrue.

The Pirates (opera): The Pirates is an opera by composer Stephen Storace with an English libretto by James Cobb.  The work was partly adapted from Storace's 1786 opera, "Gli equivoci" and is remarkable as affording one of the earliest instances of the introduction of a grand finale into an English opera.  The work premiered at the Haymarket Theatre on November 21, 1792.  The opera became a huge success and is considered by many music critics to be Storace's best composition.  It was chosen as the starring prima buffa to be performed for King George III at the King's Theatre, London on 16 May 1794.

The Palace of Truth: The Palace of Truth is a three-act blank verse "Fairy Comedy" by W. S. Gilbert first produced at the Haymarket Theatre in London on 19 November 1870, partly adapted from Madame de Genlis's fairy story, "Le Palais de Vérite".  The play ran for approximately 140 performances and then toured the British provinces and enjoyed various revivals even well into the 20th century.  There was also a New York production in 1910.

Battle of Pig Point: The Battle of Pig Point, Virginia was an engagement between the Union gunboat USRC "Harriet Lane" and a shore battery and rifle company of the Confederate Army on June 5, 1861 in the third month of the American Civil War.  Pig Point is located in Portsmouth, Virginia at the mouth of the Nansemond River near Hampton Roads, Virginia.  This location is about 5 mi from Newport News, Virginia.  The engagement occurred before any significant battles, other than the opening Battle of Fort Sumter, had taken place and received some notoriety at the time.  The action was essentially inconclusive, but the Confederates repulsed the Union gunboat's attack, and the defenders' gunfire wounded five of its crew.  Like other early engagements between Union gunboats and Confederate shore batteries, the battle at Pig Point was an early Civil War military action in connection with the blockade by the Union Navy of the Southern States in general and Chesapeake Bay in particular.  Correspondingly, it was part of the effort by Confederate forces to deny the use of rivers in Virginia to Union military and commercial traffic.

Henry VI, Part 2: Henry VI, Part 2 (often written as 2 Henry VI) is a history play by William Shakespeare believed to have been written in 1591 and set during the lifetime of King Henry VI of England.  Whereas "1 Henry VI" deals primarily with the and the political machinations leading up to the Wars of the Roses, and "3 Henry VI" deals with the horrors of that conflict, "2 Henry VI" focuses on the King's inability to quell the bickering of his nobles, the death of his trusted adviser Humphrey, Duke of Gloucester, the rise of the Duke of York and the inevitability of armed conflict.  As such, the play culminates with the opening battle of the War, the First Battle of St Albans.

Supporting paragraphs: The Wars of the Roses (adaptation) Henry VI, Part 2
Answer: First Battle of St Albans