Flevus

, the right branch of the Rhine, which formed a large lake on its falling into the sea called Flevo , now Zuider-Zee . It was afterwards called Helium , now Ulie , when its breadth became more contracted, and a fort erected there obtained the name of Flevum Frisiorum . Tacitus , Annals , bk. 2 , ch. 6 ; bk. 4 , li. 72 .— Pliny , bk. 4 , ch. 15 .— Mela , bk. 3 , ch. 2 .