Jamieson, Fausset and Brown on Mark 6:32

32. And they departed into a desert place by ship privately--"over the Sea of Galilee, which is the Sea of Tiberias," says John (Joh 6:1), the only one of the Evangelists who so fully describes it; the others having written when their readers were supposed to know something of it, while the last wrote for those at a greater distance of time and place. This "desert place" is more definitely described by Luke (Lu 9:10) as "belonging to the city called Bethsaida." This must not be confounded with the town so called on the western side of the lake (see on Mt 11:21). This town lay on its northeastern side, near where the Jordan empties itself into it: in Gaulonitis, out of the dominions of Herod Antipas, and within the dominions of Philip the Tetrarch (Lu 3:1), who raised it from a village to a city, and called it Julias, in honor of Julia, the daughter of Augustus [Josephus, Antiquities, 18.2,1].