When Judas Maccabeus led the Israeli victory over the syrian Secuelids (the syrian dynasty which followed Alexander the Great), the crowds celebrated his victory by waving palm branches, and to commemorate the victory, Judas “The Hammer” stamped an image of palm branches into their coins, thenceforth symbolizing victory for the Jews over their oppressors. So when about 150 years later, the Lord Jesus Christ was greeted to Jerusalem by thousands of followers, waving palm branches and shouting hosanna (which means please help us now), the Roman authorities must have smelled the potential for revolution, except that they knew Jesus had consistently preached that His Kingdom was, at that time, not of this world, that He was here to fulfill the promise to Abraham, that all nations would be blessed by the seed of Abraham, the promised Messiah, Jesus Christ.
So the Jews who wanted a military victory over their Roman occupiers were disappointed, while other thousands of Jesus’ new followers undoubtedly were well aware that He hadn’t preached the physical overthrow of Rome, but a spiritual revolution, promised to Abraham in prophecy, and manifested when Jesus’ resurrection caused millions from many nations, including Israel, to accept Jesus Christ as the Messiah, to become born again (as Jesus instructed).
Perhaps the majority of the admirers in the crowd on Palm Sunday in Jerusalem knew that He wouldn’t then lead Israel to the physical ousting of Rome from the Holy Land, he came riding on a meek foal, as a pauper, yet the crowds waved the victory palms and shouted “help us now.” These Jews knew, from Old Testament prophecies, that this was the Messiah who would be “cut off,” as described in Daniel 9, at that point in history, but yet, they knew that He would somehow bring spiritually millions from all the nations to a saving knowledge of the Messiah, as promised by God to Abraham, so that was the coming victory for which they waved the palm branches and shouted “help us now,” not an insurrection which Jesus never called for anyway.
Those thousands of Jews who knew that Jesus was fulfilling the Messianic prophecies in the Old Testament were later to be the first born again Christians, they understood what was happening on Palm Sunday to a significant degree, so when Jesus died and resurrected, they saw the whole picture, and readily accepted Jesus as Messiah, becoming born again, and some scholars estimate that perhaps a third of Jerusalem’s population became believers, and therewith, the spread of the Gospel to all the world began. Here is a great overview of the biblical chronology http://genesisveracityfoundation.com.