Short answers, pulled from the story.
Alexandre Colonna-Walewski (1810-1868) was a Polish-French politician and diplomat who served as France's Minister of Foreign Affairs under Napoleon III. He is best known for presiding over the Congress of Paris in 1856, which ended the Crimean War and produced the Paris Declaration Respecting Maritime Law, a foundational document for modern international law of the sea.
Yes. His mother was Maria Walewska, a Polish noblewoman and mistress of Napoleon Bonaparte. Napoleon never formally acknowledged the relationship, but he decreed Alexandre a Count of the French Empire on the 5th of May 1812. In 2013, DNA haplotype evidence confirmed Alexandre's membership in the genetic male line of the House of Bonaparte.
In his final will, Napoleon expressed the wish that Alexandre enter the service of France as a soldier. Napoleon had earlier provided materially for Alexandre during his lifetime, granting him and his mother a Paris residence and a pension of 120,000 francs, along with lands in the Kingdom of Naples generating an annual income of 169,516 francs.
The Paris Declaration Respecting Maritime Law was a treaty signed at the Congress of Paris in 1856, which Walewski presided over. Its key legal innovation was allowing nations that played no part in drafting the agreement to join it afterwards by acceding to the Declaration, making it one of the first modern multilateral open treaties.
Walewski served as Minister of Foreign Affairs from 1855 to 1860, then as Minister of State from 1860 to 1863. He was a Senator from 1855 to 1865, served in the Corps Législatif, and was appointed President of the Chamber of Deputies by Napoleon III. In 1866 he was made a Duke of the Empire on a personal basis.
Alexandre Colonna-Walewski is buried at Père Lachaise Cemetery in Paris. He died of a stroke in Strasbourg on the 27th of September 1868 at the age of fifty-eight.