After the death of her husband St. Lazar at the Battle of Kosovo in 1389, Milica ruled Serbia until 1393 when her son, Stefan Lazarević Hrebeljanović, came of age to take the throne. At that time,
In 1397 she issued the "A Mother's Prayer" together with her sons at the Dečani monastery. She commissioned the repairing of the bronze horos of Dečani.
In later diplomatic negotiations with Sultan Bayezid I, Eugenia and Euphemia, the former Vasilissa of Serres, both traveled to the Sultan's court in 1398/99.
In 1403, Eugenia went to the Sultan at Serres, arguing in favour of her son Stefan Lazarević in a complicated dispute that had emerged between her two sons and Branković.
She was buried in Ljubostinja, her monastery. She was canonized by the Serbian Orthodox Church. Princess Milica was also a writer. She wrote several prayers and religious poems. It appears that her grief and loneliness were captured in her highly lyrical and poetic address to Prince Lazar (Hrebeljanović). Although conceived as a church hymn, it contains a personal note and lyrical tones unusual for solemn and somber church hymnody.
St. Milica is the patron of writers (especially religious ones) and poets.
A slava is very popular among Serbian Orthodox faithful. Since St. Milica is one of the patron saints of Serbia, consider hosting a slava in her honor.