HERE he stands. She cannot do otherwise ... Mangling the words and the exchanging of sexes in Martin Luther’s most famous statement, might be an indulgence that is unforgivable, but its contrived nature does testify sincerely to a glorious achievement.

First, Luther not only strides though the pages of this biography but ultimately stands tall, defiant and wonderfully vibrant. This is Luther in all his worldly glory, his spiritual turbulence and his personal failing.

Second, the biography seems the realisation of Roper’s professional and personal experience. It is marked with the sort of learning one would routinely associate with a regius professor of history at Oxford University but is also imbued with an individual stance honed by the author being the daughter of a cleric to whom the book is dedicated. The conviction of her efforts suggests this was a book she had to write.

Roper states in the introduction that she seeks to examine the inner life of Luther, much of it moulded by his reactions to his father, and she succeeds both in avoiding the clichés of psychoanalysis and in bringing her subject into a light that both illuminates his greatness but reveals his flaws.

There has to be, of course, an adherence to the chronology and contests of the Reformation and the development of Lutheranism. These passages are merely excellent, Roper gently guiding the reader through the maze of free will, Luther’s insistence on the presence of Christ in the Eucharist and the much more simple scandal of indulgences for sale that was the catalyst for an event that changed the world.

She is brilliant, however, at resurrecting Luther and placing him in all his pomp, genius and sometimes virulent hate at the centre of a period of extraordinary history. No previous biography has, in this correspondent’s view, made Luther so thrillingly real. He stands before us in Leipzig carrying a bunch of flowers for no apparent reason, he looms threadbare and apparently physically feeble at the Diet of Worms and then he sits comfortably, fleshy, paternal and powerful in Wittenburg.

These are but three of the set pieces in a meticulously crafted biography that bristles with fascinating detail from an account of how Little Hans, Luther’s uncle, would go from one bar fight to another to introducing Johan Hilten, a renegade monk who would write love letters in his own blood, to featuring Lucas Cranach, the elder, the redoubtable artist who supplemented his income by selling drugs.

However, Luther dominates a cast of characters from Pope to pleb. from royalty to disaffected intellectual. He is a giant in a time of formidable friends and powerful adversaries. His rise was dramatic and aided by both his inner power and the developments of a world in revolution. From a middle-class family who made money out of mining, Luther was thus provided with a paid education. His intellect was sharpened and his religious vocation awakened. Luther defied his father to become a monk. It was the first, major sign of his willingness to challenge authority figures. It was a trait, even an aptitude that would stay with him for all of his life, regularly finding an outlet in venting at the Pope among others.

He was also a genius. It is almost fashionable now to discuss Luther’s bravery and perseverance. Certainly, he was both courageous and resilient, putting his life in danger on many occasions because of his inability to recant. But his sheer intelligence is sometimes overlooked. This is a man who can be said to have formed, or at least influenced heavily, the modern German language. His translation of the New Testament, completed in a brisk 11 weeks, shaped a language out of competing dialects. He later went on to translate the Old Testament, though this understandably was a longer shift.

His writing and translation achievements, of course, were made conspicuous by the invention of a viable form of printing. The influence of Luther can be gauged by appreciating that he was responsible for 20% of the works published in German between 1500 and 1530. His genius chimed with technological innovation, a coincidence or a sign of God’s will according to individual opinion.

The birth of the Reformation, an event that placed the Western world in turmoil, is dated to Luther nailing his theses to the door of the Castle Church in Wittenberg on October 31, 1517. Roper points out that these may have been glued to the door or even not attached at all. Luther never made any mention of such a dramatic event, instead he said he had sent letters to the archbishop of Mainz and the bishop of Brandenburg. She is, of course, aware that the physical form of his protest is the least interesting aspect of Luther but mentions it to underline that nothing about the great man can be taken on faith.

This is a biography of ideas but, blessedly, it is also the recreation of an extraordinary figure. There must, then, be an investigation of theological precepts. It would be as senseless to cavil at these at to complain that there was too much football in a biography of Pele. Roper moves through this field deftly, aware that it is always in danger of being turned into a marsh.

She always keeps her eye on Luther, though. He is at the centre of any discussion. His religiosity is examined minutely but with a commendable freshness. There is paradox and seeming contradiction in his life. He was a scrupulous, celibate monk who married a nun and enjoyed sex. He was a pious man who could joke about the sex life of Christ. He was an intellectual who could write the most powerful letters on religious matters while also detailing the precise state of his piles. He was a supplicant who lifted his eyes in prayer to God but who had a major epiphany on his privy. He was a character of strong will who tended to bow, in mundane matters, to the authorities.

He was also a man of God who retained a vicious, visceral hatred for Jews. Roper is perfectly and characteristically judicious in this awful failing. Luther detested the Slavs – “the worst nation of all" – but deployed the full force of his invective towards the Jews. Luther lived in a world that presaged a dreadful future Germany. The Slavs were derided, the Jews forced to wear the identifying tags of yellow circles. But Roper properly points out that Luther’s anti-Semitism was beyond even the desperate norms of his time.

This was the mark of another of his traits. He was an energetic, tireless hater. He railed against friends, enemies and, most enthusiastically, against the Pope. He was never one for easy conciliation and this is key to any understanding about him and his influence on history.

His statement at the Diet of Worms that resounds down the ages was added by supporters rather than recorded in official documents. Luther states he cannot retract anything, cannot go against conscience, concluding: “I cannot do otherwise, here I stand, may God help me, Amen.”

He may not have said these words but he certainly lived them. Luther’s spiritual search was accompanied by headaches, illness and what now would be described as a mental breakdown. He always recovered, even prospered in terms of religious growth. But his message was never comforting. He could never blame a person for sinning because that, he believed, was the unremitting destiny of man.

Luther held that he and mankind could only be saved by the grace of God, not through any philanthropy or exercise of individual will. He both craved and feared God. His greatest, most persistent dread was that his faith would fail him, that his belief would melt away under assaults from Satan. He derided reason as a “whore”. Every answer was in scripture, he attested.

He faced God alone. As Roper makes clear in a peerless biography, he could not do otherwise.