Short answers, pulled from the story.
Giuseppe Verdi arrived in Paris on the 27th of July 1847 with the specific goal of adapting his existing Italian opera I Lombardi alla prima crociata into a French grand opera titled Jérusalem. This decision marked a pivotal moment in the composer's life as he sought to navigate the complex world of the Paris Opéra.
Giuseppina Strepponi helped Giuseppe Verdi with the music for Jérusalem to the extent that a handwritten love duet in the composer's autograph score contains alternative lines in her handwriting. She sang the first Abigaille in Nabucco in 1842 and continued on and off with that role up to her retirement and move to Paris in October 1846.
The opera Jérusalem received its premiere performance at the Salle Le Peletier in Paris on the 26th of November 1847. The maiden production was designed by Paul Lormier for costumes and featured Gilbert Duprez as Gaston, Viscount of Béarntenor.
The story of Jérusalem unfolds in 1095 and 1099 AD, beginning in Toulouse and moving to Palestine near Jerusalem. The narrative centers on the First Crusade and involves characters such as Gaston, Roger, and Hélène.
The UK premiere of Jérusalem took place by Opera North on the 31st of March 1990 at the Grand Theatre in Leeds. It took over 140 years for the opera to be given its UK premiere after its initial 1847 performance.