"Provicia Palaestina" was the name given by the
Romans to Provincia Iudaea, after the 132
CE rebellion of the
Jews against them failed, the name appears nowhere before. Many
Jewish cities in the area were sacked at that time, including
Jerusalem, which was renamed "
Ilia Capitolina", and their Jewish inhabitants deported.
The Romans chose to call the province after the philistines, although they were long since extinct by that time. By the changing of the name the Romans hoped to disconnect the Jewish people (Populus Iudaeus in Latin) from their homeland, since the Jews were considered by that time a dangerous element (The 132 CE rebellion was the third Jewish rebellion against the Romans).
The term actually included the territories of what are now both Israel and Jordan. The British mandate in Palestine included the territories of both future states, and only in 1946 did the British government decide to cut off of the Palestine mandate the territory that was first called Transjordan and later The Hashemite Kingdom of Jordan.