Short answers, pulled from the story.
Lord Ellenborough issued a directive on the 12th of January 1830 marking the formal beginning of British strategic engagement in Central Asia. This administrative order created a new trade route leading directly to the Emirate of Bukhara.
Captain Arthur Conolly coined the term the Great Game in 1840 while serving as a political officer. He wrote to Major Henry Rawlinson in July 1840 describing their shared mission as a great game and noble game.
American historian David Fromkin identified nine reasons for British war anxiety including fear that Russia would invade India or disrupt established trade routes. Petroleum deposits discovered in central Asia in the early 20th century became essential for the Royal Navy.
General Konstantin Kaufman led campaigns that extended influence into outlying regions of Afghan Turkestan. Notable generals included Mikhail Skobelev and Mikhail Chernyayev who participated in various military operations between 1864 and 1873.
The First Anglo-Afghan War began when Britain marched into Afghanistan in 1838. A Kabul garrison of 4,500 troops and 12,000 camp followers left for Jalalabad on the 8th of January 1842 but were attacked by 30,000 Afghans resulting in the destruction of the Army of the Indus.
Great Britain and Russia signed an agreement defining spheres of influence on the 21st of January 1873 which stipulated eastern Badakhshan area as Afghan territory. The Delimitation Protocol Between Great Britain and Russia was signed in London on the 10th of September 1885 followed by nineteen additional protocols between 1885 and 1888.