Who were the main Protestant precursors? While Martin Luther is the origin of a particular protestant-reformist movement named Lutheran and of its derivative churches, it's unclear to me whether he should be considered responsible to the entire protestant reformation.

Considering Luther's venomous antiseminitism, it is further unclear to me because many so called Protestant movements are Judaism oriented ranging from the Seventh Day Adventists, to the Messianic Jews, to some Black Hebrew Israelites.

Were there precursor movements to Martin Luther which generally shared concepts of the Lutheran movement, but which remained independent from it to modern times?
No, Luther certainly should not be viewed as "responsible [for] the entire protestant reformation". Throughout previous centuries, various non-Catholic church groups held to some beliefs that came to be recognisable as Reformation theology and practice. However, that subject is so vast, it cannot possibly be covered here. I recommend you study the book "The Pilgrim Church" by E.H. Broadbent (Pickering Classic first published in 1931 through to 1985 at least.)

Prior to the reformation starting, Catholic scholar Erasmus (1467-1536) was a serious editor of Latin and Greek texts and produced an epoch-making edition of the Greek New Testament (the first ever printed and published, in 1516, the year before the Reformation began). The Romanists furiously blamed him for ‘letting Luther happen’. He was spoken of obliquely as "The egg that Luther hatched".

In 1505 Erasmus had published Valla’s work as ‘Adnotationes in Novum Testamentum’. Valla had earlier incurred displeasure in Rome by showing to be a mere fable the supposed MSS relating to a ‘Donation of Constantine’ bestowing temporal power with the Bishops of Rome. Valla declared that theologians must work from the grammatical sense for the meaning of the text, to which Erasmus agreed.

Erasmus next travelled a lot, searching for Greek NT MSS, and then managed to construct a single continuous text of the Greek NT through comparisons and collation of a few MSS.  His 1516 edition had his version of the Latin Vulgate NT, supported in a parallel column by his newly compiled text of the Greek NT. He used the Greek as a plumb line to vindicate his Latin differences. Many valid criticisms of his work were admitted to by Erasmus himself from the start. A fourth, improved edition was later produced.

Before Luther got going, Erasmus had produced his NT in its original Greek. Luther got the printed text in Wittenberg as he was lecturing on the 9th chapter of Romans. From Erasmus's accompanying translation he learned of the inaccuracy of the Vulgate rendering of 'do penance' instead of 'be penitent'.

Erasmus and Luther had much in common. Both insisted that the church of their day had relapsed into a Judaistic type of legalism condemned by the apostle Paul. Christianity, said Erasmus, has been made to consist not in loving one's neighbour but in abstaining from butter and cheese during Lent. What good are indulgences to those who do not mend their ways? Both men had a quarrel with the pope, Luther because the pontiffs imperilled the salvation of souls, Erasmus because they fostered external ceremonies and, at times, impeded free investigation.

Poor Erasmus ended up falling between two stools – the Romanists blamed him furiously for ‘letting Luther happen’. He was spoken of obliquely as "The egg that Luther hatched". But the Lutherans could not accept his not falling in with Luther.
Article by C.P. Hallihan in Issue No. 615, April-June 2016, Quarterly Record (Trinitarian Bible Society) 

My material is a combination from that article and the book "Here I Stand - Martin Luther" by Roland Bainton (Lion Publishing 1978). As for your second question about Luther's antisemitism, that is also admitted to in Bainton's book. 


  "He had earlier believed that contemporary Jews could not be blamed
  for the sins of their fathers, and sympathised with why they hated
  Catholicism so much; “We should use toward the Jews not the pope’s but
  Christ’s law of love.” Sadly, he came to change that view when his
  endeavour to proselytize some rabbis failed. A rumor that a Jew had
  been suborned by the papists to murder him was believed. Later, news
  came that in Moravia, Christians were being induced to Judaize. Then
  he came out with a vulgar blast in which he recommended that all Jews
  be deported to Palestine. Failing that, they should be forbidden to
  practice usury, should be compelled to earn their living on the land,
  their synagogues should be burned, and their books (including the
  Hebrew scriptures) should be taken from them. One paragraph reads,
  "Therefore be on your guard against the Jews, knowing that wherever
  they have their synagogues, nothing is found but a den of devils in
  which sheer self¬glory, conceit, lies, blasphemy, and defaming of God
  and men are practiced most maliciously and veheming his eyes on them."


That tract is a shame and no excuse is offered. Quote from p379-380 of Bainton's book. Many Protestant groups today would offer no excuse for Luther's antisemitism either. We are far removed from Luther's era and popular attitudes in Europe back then. I hope this goes some way to answering your questions, the scope of which is vast.