Short answers, pulled from the story.
The Republic of Genoa participated in the First Crusade starting in 1097 when twelve galleys and one ship carrying 1,200 soldiers set sail from Genoa. The Genoese fleet blockaded Antioch in May of that year and helped capture the city on the 3rd of May 1098.
The Republic of Genoa signed a treaty with Michael VIII Palaiologos emperor of Nicaea in March 1261 that led to the recapture of Constantinople on the 25th of July 1261. This agreement granted Genoa free trade rights in the Nicene Empire and ports across many islands and settlements in the Aegean Sea.
The Battle of Meloria took place in August 1284 where the Genoese fleet defeated the Pisan fleet led by Albertino Morosini and Ugolino della Gherardesca. This victory resulted in Genoa gaining control of Corsica's commerce and turning Sassari into a commune controlled by Genoa while killing about 8,000 Pisans.
The Bank of Saint George was founded in Genoa in 1407 becoming the oldest state deposit bank in the world until its closure in 1805. Another institution called the mount of piety opened in 1483 and still exists today.
From 1339 until extinction in 1797 the ruler of the republic was the doge originally elected for life but after 1528 elected for two-year terms. The state functioned as an oligarchy ruled by a small group of merchant families selected from whom the doges came including noble houses like Grimaldi Spinola Durazzo De Franchi Giustiniani and Lomellini.
In May 1797 Genoese Jacobins aided by French volunteers moved to overthrow Doge Giacomo Maria Brignole triggering fratricidal warfare in the streets. Napoleon's representatives intervened in early June when old elites ruling all of history were overthrown and on the 14th of June 1797 the Ligurian Republic was proclaimed under Republican France's watchful care.