The list of the Grand Princes of the Magyars in the first half of the 10th century is incomplete, which may also prove a lack of central government within their tribal federation. The medieval chronicles mention that Grand Prince Árpád was followed by his son, Zoltán, but contemporary sources only refer to Grand Prince Fajsz (around 950). After the defeat at the Battle of Lechfeld, Grand Prince Taksony (in or after 955 – before 972) adopted the policy of isolation from the Western countries – in contrast to his son, Grand Prince Géza (before 972–997) who may have sent envoys to Otto I, Holy Roman Emperor in 973.