As the Middle Ages were approaching their peak, the pope grew in prominence beyond any king in Christendom.  The spiritual life of the Church was in the process of renewal, but there was still ignorance and division that threatened to get worse.  In the year 1170, the same year in which Saint Thomas Becket was martyred in England, Dominic de Guzman was born in Calarogo, now Caleruega, Spain, about 20 miles from the Cathedral in Osma.

Before his mother conceived him, she saw in a vision that a dog with a burning torch in its mouth would come forth from her womb and set the world aflame.  Later, she saw the moon on his forehead, yet at his Baptism, his godmother perceived it as a star.  The boy was christened probably after Saint Dominic of Silas whose nearby shrine was a favorite of his mother.

His parents were Blessed Jane or Joan of Aza, renown for her charity to the poor and her miracles, and a nobleman named Felix de Guzman.  They lived in a tower in the little village of which they were the royal wardens.  Their eldest son Anthony would become a Canon of Saint James, and their second, Mannes, would eventually follow his younger brother in the Order of Preachers.  Mannes was later beatifide.  Two nephews of Dominic would also join the Order, sons most likely of his sister.  As a boy, Dominic was sent to his mother's brother to receive instruction for seven years.  His uncle was a parish priest in Gumiel d'Izan.  Even as a child, Dominic avoided games and denied himself the comfort of a bed to sleep on the floor.

At the age of 14, he went to the university in Palencia, in the kingdom of Leon.  Around that time, there was a terrible famine.  To give alms to the poor, he sold his possessions, even his precious annotated books, thinking that the living skins of the famished were more important than the dead skins of his books.  Music was studied in the quadrivium.  Consequently Dominic loved to sing, particularly the Ave Maris Stella and the Veni Creator.  His study of the arts lasted six years.

Then in 1190, he was appointed to the canonry at Osma, while pursuing theological studies.  Around five years later, he was ordained to the priesthood.  The Canons Regular were essentially clerics who customarily followed the Rule of Saint Augustine.  He continued with this life for another nine years.  During his nightly vigils, Father Dominic grew in holiness as he wept for sinners.  Of the many books he read, he was particularly fond of the Conferences of the Desert Fathers by Cassian.  When Dominic was 31 years old and the subprior of his community, his prior, Diego d'Azevedo, succeeded the Bishop of Osma.

Dominic accompanied his holy bishop in 1203 to the Marches of France, in the Languedoc region, because of a royal wedding.  It was there that they were struck by the spread of falsehood.  People were adopting Albigensianism which considered all material things to be evil.  While at Toulouse, Dominic stayed up all night until he had persuaded the innkeeper to accept the true faith.  About that time, the pope had called upon the Cistercian abbots to preach against this heresy.  At Montpellier, Bishop Diego convinced them to abandon their ostentatious retinues.  He himself put on the Cistercian habit and joined the mission, taking Dominic with him.  From then on, the subprior was called "Brother Dominic."

The preachers held disputations from town to town, attended by the lowly and the noble alike.  At Fanjeaux, arbiters held a trial by fire for the manuscripts written by Dominic and his adversaries.  The one written by Saint Dominic flew out of the flames three times.  A similar miracle took place at Montreal.

The Albigensians were extremely austere, but Dominic surpassed them all by his charitable sacrifices.  He might eat a bit of dried fish or a little bread and soup.  Women who often fed him testified that he never ate more than two eggs, and his wine was about two-thirds water.  Dominic wore an abrasive hairshirt, and had an iron chain forged around his waist.  He slept very little, and when he did, it was always on the floor, preferably in the chapel.  There, the fire of the Holy Spirit even dried his rain-soaked habit better than those of his companions who spent the night by the fireplace.  Exhausted from his vigils, he sometimes napped on the side of the road.  It was his practice to carry his shoes until he got to town.  Once when he needed directions, people maliciously sent him along a path of briars, but he was always happy to bear a little more for the love of God.

Dominic once told a pompous bishop, "... heretics are more easily won over by examples of humility and virtue than by external display or a hail of words.  Should we not rather arm ourselves with devout prayers and, carrying before us the standard of true humility, proceed in our bare feet against Goliath?"  As hard as he was on himself, nevertheless, Dominic was easy on others.

On the night of July 22, 1206, the feast of Saint Mary Magdalen, on a hill of Fanjeaux overlooking the little town of Prouille on the plain, Saint Dominic saw what appeared to be a globe of fire descending upon a shrine of Our Lady.  The sign from Our Lady (or sign of God, "Seignadou" in the local dialect) occurred again the next two nights.  From this, he understood that he was to establish a monastery of nuns at Prouille.  In the months that followed, Dominic converted nine young women.  Consequently, the first "Dominican" convent opened on the 27th of December.  Saint Mary Magdalen, the penitent Apostle to the Apostles, therefore, would become the patroness and mother not only of the converted nuns of Prouille but of the Order of Preachers about to be born.

Bishop Diego returned to his diocese in 1207, but died soon after.  Saint Dominic then took charge of the small band of preachers.  Already at Prouille, there was a double monastery or priory next to the monastery, but the brothers were not yet bound to Dominic canonically.  Unfortunately in 1208, servants of an Albigensian count murdered a papal legate, giving the heresy more political significance.  As a result, the mission turned into a bloody crusade in the hands of aristocrats and their armies.  In the course of the war, Churches were burned, and the preachers disbanded.  Dominic, often alone, continued at the task for years, all the while serving the victims of violence.

Brother Dominic always hoped to be martyred but thought himself unworthy.  So, he fled places of honor and drew near to mistreatment, to where people would spit and throw filth at him.  Aware of looming ambush, he approached singing in plain view.  His courage and faith, however, intimidated assassins.

At Muret, the Catholic force was vastly outnumbered, but they broke through the enemy line, killed the heretical King of Aragon and won a great victory, just as Dominic had foretold.

In 1211, while the war continued , a group of English pilgrims were on their way to Saint James of Compostela in Spain.  While crossing the River Garonne, the overloaded boat capsized.  Dominic, in a nearby church, heard the cries of bystanders and soldiers.  Many of the pilgrims were already underwater.  Dominic prostrated himself, prayed and loudly commanded their safety in the Name of Jesus Christ.  Immediately, the pilgrims emerged near the shore and were pulled to the riverbank.  One of the pilgrims, named Lawrence, would be one of the first members of the Order of Preachers.  In another incident, a ferryman demanded payment from Dominic, who then prayed and picked up a coin at his feet.  Later, eyewitnesses would testify to these and many other miracles at his canonization process.

At Castres, Dominic was praying in the church.  The prior sent one of the canons to fetch him for dinner.  Seeing Dominic floating in the air, he returned to tell the prior who went to see for himself.  So moved was he by the phenomenon, the prior, Matthew of France, became another of Dominic's first followers.  Eventually, a new group of preachers gathered to support his mission.