Isaiah is the greatest of all the prophets. 

Even though Isaiah was not, sequentially, the first prophet, the depth of his thoughts, the beauty of form and the power of his language, the wealth and the importance of his prophecies place him ahead of all those who have proclaimed God’s mysteries.  His hometown was probably the capital, Jerusalem. There he belonged to the distinguished circles and was close to the royal house. Of his family, only his father Amos and two sons with prophetic names are mentioned.  He worked for four very different kings: Oziah, Joah, Ahaz and Hezekiah for a full forty-five years.  Already in the year of the death of Oziah, 738 AD, he received his calling to prophecy in the form of an impressive vision.  He saw himself in the forecourt of the temple standing entranced at the entrance to the sanctuary, looking at the curtain before the holiest of holies. There he saw the Lord in impenetrable light - not actually the Lord himself, but the hem of his robe that filled the sanctuary, and, floating above him, two gleaming winged forms... The Lord asked: “Whom shall I send?” and the young Isaiah answered plainly and simply but decidedly, "I am ready, send me!”.  What else God had said to him, he kept to himself, for it was most discouraging for himself and so crushing for the people: He was not to preach conversion, but callousness to the people, to render them both deaf and blind, until such time as the courts interfered and punished them, where after there would remain only a small fragment as “holy sperm” for the future. With outrageous frankness he told the people exactly how things stood.    
Falling back on an old prophecy which his contemporary Micah (4.1-3) too had used, he described in brief the peaceful Messianic end of time, when all people would come to God’s mountain, to recognize the truth, and accept His law.  And the renegade present will be given an advance warning in the form of a terrible thunderstorm of the punishment awaiting it on the day of judgement .
With the picture of the high-spirited wine-harvest in the song of the barren vineyard of his friend, he describes to King Joatham his religious barrenness (exterior prosperity goes hand in hand with inner distance from God – as applies to the present day also!) along with the main sins: greed, lack of moderation, insolence, dishonesty, haughtiness and corruptibility.  Isaiah surprises with the universality of his intellect, the width and depth of his prophecies, the variedness of his feelings and thoughts  ... from sweetest joy to most bitter pain.  A central figure of the Old Covenant, he was a contemporary of the decline of the Northern Empire and experienced the miraculous rescue of the Southern Empire, yet he also prophesied its disaster and the rescue of only a small fraction thereof … which he lovingly took responsibility for and to which he revealed the picture of the messianic servant of God (see John the Baptist, the Messiah Jesus Christ read from his scroll at Nazareth ...).  Thus Isaiah became the greatest of the prophets of both testaments, an exalted example of the God-given gift of prophesying which in the oracles of the heathen world groped futilely in darkness.  He was elevated by God’s worshippers to the brilliant summit of divine revelation.