With the ability to grow food and the acquisition of land by conquest, for instance by invading Angles and Saxons, the population grew. There were different classes of men such as eorls, ceorls [free farmers], and slaves. They dressed differently. Freemen had long hair and beards. Slaves' hair was shorn from their heads so that they were bald. Slaves were chained and often traded. Prisoners taken in battle, e.g. Britons, became slaves. Criminals became slaves of the person wronged or of the King. Sometimes a father pressed by need sold his children or his wife into bondage. Debtors, who increased in number during famine, which occurred regularly, became slaves by giving up the freeman's sword and spear, picking up a slave's mattock [pick ax for the soils], and placing their head within a master's hands. Children with a slave parent were slaves. The slaves lived in huts around the homes of big landholders, which were made of logs and consisted on one large room or hall. An open hearth was in the middle of the earthen floor, which was strewn with rushes. There was a hole in the roof to let out the smoke. Here the landholder and his men would eat meat, bread, salt, hot spiced ale, and mead while listening to minstrels sing about the heroic deeds of their ancestors. Physical strength and endurance in adversity were admired traits. Slaves often were used as grain-grinders, ploughmen, sowers, haywards, woodwards, shepherds, goatherds, swineherds, oxherds, cowherds, dairymaids, and barnmen. A lord could kill his slave at will. The people were worshipping pagan gods when St. Augustine came to England in 596 A.D. to Christianize them. King AEthelbert of Kent and his wife, who had been raised Christian on the continent, met him when he arrived. The King gave him land where there were ruins of an old city. Augustine used stones from the ruins to build a church which was later called Canterbury. He also built the first St. Paul's church in what was later called London. Aethelbert and his men who fought with him and ate in his household [gesiths] became Christian. Augustine knew how to write, but King AEthelbert did not. The King announced his laws at meetings of his people and his eorls would decide the punishments. There was a fine of 120s. for disregarding a command of the King. He and Augustine decided to write down some of these laws, which now included the King's new law concerning the church.