 With her main supporter Leo Phokas crushingly defeated by the Bulgarians at the Battle of Acheloos in 917, Zoe started to lose ground.Embarrassed by further failures, she and her supporters were supplanted in 919 by the admiral Romanos Lekapenos, who married his daughter Helena Lekapene to Constantine VII and finally advanced to the imperial throne in 920.The Patriarch Nicholas came to be one of the strongest supporters of the new emperor, and took the brunt of renewed negotiations with the Bulgarians until his death in 925.