Countess Anne of Nassau-Siegen (1440 or 1441 – 5 or 8 April 1514), , official titles: Gräfin zu Nassau, Vianden und Diez, Frau zu Breda, was a countess from the House of Nassau-Siegen, a cadet branch of the Ottonian Line of the House of Nassau, and through marriage successively Duchess of Brunswick-Lüneburg and Countess of Katzenelnbogen. She acted as regent of the Duchy of Brunswick-Lüneburg for her son in the period 1479–1486. Biography It is not known where and when Anne was born, some reasons suggest that she was born at the end of 1440 or 1441. She was the eldest daughter of Count John IV of Nassau-Siegen and his wife Lady Mary of Looz-Heinsberg. Anne married on 28 October 1467 to Duke Otto II ‘the Victorious’ of Brunswick-Lüneburg (1439 – January 1471), who had succeeded his brother Duke Bernard II in 1464. As her dower she received the . Anne already became a widow in January 1471. Her son Henry succeeded his father. As Henry was still a minor, he was under the custody and regency of his paternal grandfather Duke Frederick II ‘the Pious’, who had been in a monastery since 1457. Anne had her dower rebuild between 1471 and 1473. Anne remarried on 24 January 1474 to Count Philip ‘the Elder’ of Katzenelnbogen (1402 – 28 July 1479). Philip had previously married on 24 February 1422 to Countess Anne of Württemberg (d. 16 April 1471). From his first marriage Philip had three children. The eldest son, Philip ‘the Younger’, had married Anne’s first cousin Ottilie of Nassau-Siegen, but died already in 1453. The second son Eberhard died three years later. Finally there was a daughter, Anne, who was married to Landgrave Henry III ‘the Rich’ of Hesse-Marburg. Anne’s second marriage was arranged by Anne’s parents with the cooperation of the estates of the realm of the County of Katzenelnbogen. If a son had been born from the marriage between the 72 years old Philip and the 32 years old Anne, the later seizure of the County of Katzenelnbogen by the Landgraviate of Hesse, which had its legal basis in the marriage of Philip’s daughter Anne to Henry III of Hesse-Marburg, could have been avoided. This would have been entirely in the interest of the Counts of Nassau. The marriage contract stipulated that Anne should receive an annual income of 1600 guilders in interest and in kind as