The Mu'tazilites were the early Muslim rationalists (well, kind of), and they held that the Quran was created. They lost out in the long run, but the Mu'tazilite Controversy was formative for all subsequent Islam (like the Arian Controversy for Christians). The Arian controversy originated in Alexandria and the Mu'tazilite controversy in Basra.
...the Mu‘tazilites concluded that the Qur’an had been created (makhluq). The argument may be reconstructed as follows: if the Qur’an is God’s speech, then it is either coeternal with God, and thus uncreated, or it is not coeternal with God. To maintain pure monotheism one must concede that it is created. On this inference, if the Qur’an is coeternal with God, then in order to eschew plurality in the divine
oneness, one has to say that the scripture, as God’s speech, is one with
God. To avoid affirming contraries (unity and multiplicity), a Mu‘tazilite
would assert that it is not coeternal with God and must therefore be
created. This argument is seconded by qur’anic proof-texts that point to
the descent of revelation in the Arabic tongue that is constrained by
place and time, as to its accessibility to finite human apprehension.
The Cambridge Companion to Classical Islamic Theology, Ch. 6
