Short answers, pulled from the story.
Joséphine de Beauharnais, born Marie-Josèphe-Rose Tascher de La Pagerie on the 23rd of June 1763, was the first wife of Emperor Napoleon I and Empress of the French from the 18th of May 1804 until their marriage was annulled on the 10th of January 1810. She was also Queen of Italy from 1805 until the annulment.
"Beauharnais" was the surname of her first husband, which she dropped when she married Napoleon and took the name Bonaparte. The misnomer "Joséphine de Beauharnais" emerged during the restoration of the Bourbons, who would not refer to her by Napoleon's surname or her imperial title. Before meeting Napoleon she went by Rose, and Napoleon was the first to call her Joséphine.
Napoleon had the marriage annulled because Joséphine did not bear him any children. After his declared heir and her grandson Napoléon-Charles Bonaparte died of croup in 1807, he sought a wife who could produce an heir. The divorce ceremony took place on the 10th of January 1810, and he later married Marie-Louise of Austria.
Her first husband, Alexandre de Beauharnais, was guillotined on the 23rd of July 1794 on the Place de la Révolution in Paris during the Reign of Terror. He had been accused of poorly defending Mainz in July 1793. Joséphine, imprisoned in the Carmes Prison, was freed five days later after the fall of Robespierre.
Joséphine bought the Château de Malmaison in 1799 and built a famous rose garden, aiming to collect every rose then known. She commissioned Pierre-Joseph Redouté to paint her flowers in Les Roses, supported modern rose hybridizing by her horticulturist André Dupont, and is believed to have hosted the first rose exhibition in 1810.
Joséphine died of pneumonia at Rueil-Malmaison on the 29th of May 1814, soon after walking with Emperor Alexander I of Russia in the gardens of Malmaison. Napoleon, exiled on Elba, learned of her death from a French journal and stayed locked in his room for two days. His last words on his deathbed at Saint Helena included her name.