Short answers, pulled from the story.
Die Entführung aus dem Serail draws its setting from North African Barbary corsairs who hijacked ships belonging to Christian states under the pretext of jihad. These corsairs acted on behalf of Muslim rulers in Algiers, Tunis, and Tripoli until state-backed piracy ended after the French conquest of Algiers in 1830.
Die Entführung aus dem Serail premiered on the 16th of July 1782 at Burgtheater in Vienna. The work had been commissioned by Austrian emperor Joseph II as part of a national Singspiel company established between 1778 and 1783.
Gottlieb Stephanie wrote the libretto for Die Entführung aus dem Serail and gave it to Wolfgang Amadeus Mozart on the 29th of July 1781. Stephanie prepared an altered version without seeking permission from Christoph Friedrich Bretzner whose original material he used.
Osmin's Act 3 aria includes characteristic 18th century coloratura passage work that goes down to low D one of the lowest notes demanded in opera. Ludwig Fischer sang the role of Osmin and was noted for his wide range and skill leaping large intervals.
The first two performances brought a sum of 1200 florins making the work a huge success financially for the production. Mozart received a flat fee of 100 Imperial ducats about 450 florins earning no profits from subsequent performances despite the opera's popularity.