This is what Joseph Priestly said about the "one will" doctrine:
"The next controversy of which I shall give an account, shows, at the same time, the subtlety of the mind of man in devising distinctions, and the impotence of power to restrain or guide it. In the seventh century, the emperor Heraclius, considering the detriment which his empire received from the migration of the persecuted Nestorians, and their settlement in Persia, was very desirous of uniting the Monophysites, and thought to prevent the diversity of opinions among them by inducing them to accede to the following proposition (suggested to him, it is said, by Anastasius, the chief of the Jacobites, and who pretended to renounce Eutychianism, in order to be made bishop of Antioch), "There was in Jesus Christ, after the union of the two natures, but one will and one operation." Accordingly he published an edict in favour of this doctrine, which was called that of the Monothelites, in 630. It was afterwards confirmed in a council, and for some time seemed to have the intended effect. But soon after it was the occasion of new and violent animosities, in consequence of the opposition made to it by Sophronius, a monk of Palestine. He, being raised to the see of Jerusalem, was the occasion of a council being held at Constantinople in 680, which was called the sixth general council, in which the doctrine of the Monothelites was condemned. Not withstanding this condemnation, this doctrine was embraced by the Mardiates, a people who inhabited Mount Libanus, and were afterwards called Maronites, from Maro, their first bishop; but in the twelfth century they joined the church of Rome. In the condemnation of this doctrine, it is remarkable that it was not stated, nor anything opposite to it asserted; the writings only which contained it being condemned, as containing propositions "impious and hurtful to the soul;" and they were therefore ordered to be exterminated and burned. It is, indeed, no wonder that those who are called orthodox with respect to the doctrine of the Trinity, should be embarrassed with two intelligent principles in one person, in what manner soever they may imagine them to be united. If there be but one intelligent principle, or nature, there can be but one will, but if there be two intelligent principles, it is natural to expect two wills. But then what certainty can there be that these two wills will always coincide, and what inconvenience would there not arise from their difference?" A History of the Corruptions of Christianity, pg. 43
The Catholic Encyclopedia confirms this:
The origin of the Monothelite controversy is thus related by Sergius in his letter to Pope Honorius. When the Emperor Heraclius in the course of the war which he began about 619, came to Theodosiopolis (Erzeroum) in Armenia (about 622), a Monophysite named Paul, a leader of the Acephali, made a speech before him in favour of his heresy. The emperor refuted him with theological arguments, and incidentally made use of the expression "one operation" of Christ. Later on (about 626) he inquired of Cyrus, Bishop of Phasis and metropolitan of the Lazi, whether his words were correct. Cyrus was uncertain, and by the emperor's order wrote to Sergius the Patriarch of Constantinople, whom Heraclius greatly trusted, for advice. Sergius in reply sent him a letter said to have been written by Mennas of Constantinople to Pope Vigilius and approved by the latter, in which several authorities were cited for one operation and one will. This letter was afterwards declared to be a forgery and was admitted to be such at the Sixth General Council.
It seems this doctrine came about by an emperor named Heraclius from about 622-630 AD. He uttered something along the lines of "one operation", but he wasn't sure if it was correct. So he asked some other Catholics and they agreed to it. There are no biblical arguments for this doctrine, and Yeshua expresses a will in opposition to God's quite a few times. Examples of this are:
"Saying, Father, if thou be willing, remove this cup from me: nevertheless not my will, but thine, be done." Luke 22:42
Then was Jesus led up of the spirit into the wilderness to be tempted of the devil." Matthew 4:1