Raden Ajeng Kartini was an Indonesian national heroine born on April 21, 1879, in Jepara, Central Java. She is best known for her advocacy for women's rights and education in Indonesia during the Dutch colonial period. Kartini's letters, published posthumously as "Habis Gelap Terbitlah Terang," highlight her thoughts on gender equality and the importance of education for women. Kartini's legacy continues to inspire many in Indonesia and beyond. Her birthday is celebrated as Kartini Day on April 21 each year, honoring her contributions to women's empowerment. She is often regarded as a symbol of the struggle for women's rights in Indonesia.