Of Turkish-Albanian origin, Halil was born in Cairo, Egypt in the mansion of Muhammad Ali of Egypt. Halil's father, Muhammad Şerif Pasha, of Albanian origin, (died 13 February 1865) had emigrated to Egypt from Kavala (in what is now northern Greece) to serve as a captain in Muhammad Ali's army, making a huge fortune in the process. Muhammad Şerif Pasha sent Halil, along with his brothers Ali Pasha Sherif (1834–1897) and Osman, to be educated at the "École Militaire Égyptienne" (Egyptian Military School), which Muhammad Ali Pasha had set up in Paris in 1844. Halil took up his first official post in 1855 as Commissioner to the International Exhibition in Paris that year. He entered the Ottoman diplomatic service in 1856, serving as one of the plenipotentiaries negotiating the end to the Crimean War, and then as ambassador to Athens and Saint Petersburg, on which posts he began collecting art. He grew to dislike the cold of Saint Petersburg and so retired in a private capacity to Paris in the mid-1860s, renting expensive rooms from the English collector Lord Hertford on Rue Taitbout and becoming a noted gambler, art collector and patron.