Short answers, pulled from the story.
Jin means gold. Founder Wanyan Aguda adopted the Jurchen word for gold, alchun, as the name of his state, possibly derived from the Anchuhu River east of Harbin whose Jurchen name meant golden. The Mongols called the Jin ruler the Golden khan, and through them the Jin became the first Chinese dynasty known in Europe by their dynastic name, with Marco Polo rendering it roi d'or, gold king.
Wanyan Aguda founded the Jin dynasty in spring 1115 after leading the Jurchen rebellion against the Liao dynasty. His rise was sparked when he refused to perform a ritual dance before the Liao emperor Tianzuo at a gathering on the Huntong River in late 1112. Aguda was elected ruler of the Jurchens in 1113 and declared himself emperor after military victories against Liao forces.
The Jingkang Incident was the Jin capture of both reigning Song emperors, Qinzong and Huizong, when Jin forces broke through the defenses of the Song capital Kaifeng on the 9th of January 1127. The two emperors were demoted to commoners, forced to bow before Aguda's mausoleum, made to wear mourning dress, and given insulting titles: Muddle Virtue and Doubly Muddled. Huizong died in 1135 in Wuguocheng near the Songhua River.
The Treaty of Shaoxing, finalized on the 11th of October 1142, set the Huai River as the border between the Jin and Song, required the Song to cede Tangzhou and Dengzhou, and obligated the Song to pay 250,000 ounces of silver and silk annually. The treaty was framed as vassalage, with the Song addressing the Jin as a superior state. The Jin withdrew their armies and agreed to return the coffin of the captured emperor Huizong.
The Jin faced persistent cultural drift as large numbers of Jurchens settled in northern China and adopted Han customs. Emperor Wanyan Liang actively promoted sinification, moving the capital to Yanjing (modern Beijing) and demolishing the Jurchen ancestral palaces. Emperor Shizong reversed course by founding the Imperial Jurchen Academy, offering imperial examinations in Jurchen, and issuing edicts barring Jurchens from taking Chinese names or dress.
Genghis Khan invaded the Jin Empire in 1211, winning several early victories. The Jin had been weakened by the catastrophic 1194 Yellow River flood, ongoing wars with the Song, internal ethnic tensions, and decades of failed Mongol management that included the execution of Ambaghai Khan on a wooden donkey. Over 23 years the Jin suffered repeated military defeats, internal revolts, defections, and coups before the Mongols completed the conquest in 1234.