"Grand Duchess Catherine Pavlovna of Russia (Russian: Екатерина Павловна; 21 May 1788 [OS 10 May 1788] – 9 January 1819) later Queen Catharina Pavlovna of Württemberg, was the fourth daughter of Tsar Paul I of Russia and Duchess Sophie Dorothea of Württemberg. She became the Queen of Württemberg upon her marriage to her first cousin Crown Prince William who eventually became King William I of Württemberg in 1816." - (en.wikipedia.org 03.06.2020)
