He was the son of Marshal Antoine III de Gramont and Françoise-Marguerite du Plessis de Chivré, Richelieu's niece. His sister was Catherine-Charlotte, (1639 - 1678), Princess of Monaco and mistress of Louis XIV.
Armand was bisexual. He was part of the entourage of the homosexual Philippe d'Orleans, where many reckoned him the handsomest man at court. He was known for being vain, overbearing, and somewhat contemptuous, but many lovers of both genders often overlooked these flaws. It is generally accepted that he became the lover of Henrietta d'Orleans, but for a time he also paid court to Louise de la Vallière.
Guiche was, however, not sufficiently enamored with Louise to challenge King Louis XIV's affections for her. He was exiled in 1662 for conspiring with the jealous Henrietta d'Orleans to drive a wedge between Louis XIV and Louise.
He then fought against the Turks for Poland, against the English for the Dutch, and eventually returned to France in 1669.
He returned to court in 1671. In 1672 he joined Louis XIV and the Great Condé in the Franco-Dutch war and covered himself in glory when he swam across the Rhine, and the whole army followed his example.