Orhan I was the bey (chief) of the newborn Ottoman Empire (at the time known as the Osmanli tribe) from 1326 to 1359. Orhan conquered most of eastern Anatolia and took part of the political upheaval of the decaying Byzantine Empire by marrying Helen, the daughter of John VI Cantacuzenus the alienated guardian of Emperor John V Palaeologus. As the price of this still prestigious marriage, Orhan helped Cantacuzenus to overthrow John V and his regents. In 1354 Orhan's son Sulaiman Pasha, occupied Gallipoli (evacuated by its Greek population in the wake of an earthquake) and gave the Ottoman state a bridgehead into mainland Europe.