Alexander married a German princess for the first time. In March 1839, when he was still the heir to the throne, he met her in Darmstadt during a trip across Europe. There he got to know Princess Maximiliana Wilhelmina Augusta Sophia Maria of Hesse-Darmstadt, whom he immediately began to call simply Maria. In a letter to his father Nicholas I, Alexander wrote that Princess Maria made a strong impression on him at first sight.

It was true love at first sight, passionate and unyielding. In a letter to his mother, the Empress, Alexander wrote that he was not interested in the secrets of Princess Maria and intended to marry only her. However, Alexander's parents initially did not consent to the marriage due to certain 'secrets,' and he even threatened to renounce the throne if he was not allowed to marry the princess.

Maria Alexandrovna made a significant contribution to the development of Russia. Under her, the Red Cross was established, and she patronized numerous hospitals, almshouses, shelters, institutes, gymnasiums, and schools. The Empress played an important role in the development of women's education by opening non-class-based women's gymnasiums. She also actively participated in the emancipation of the peasants and spent significant funds on charity. During the Russo-Turkish War, she refused to buy new dresses, directing her savings to help widows, orphans, the wounded, and the sick.