Watchman Nee called it the "greatest known revival in church history." On October 31, 1904, Evan Roberts, a twenty-six-year-old former miner, returned home from a ministry training program, having quit at the urging of the Holy Spirit. That night, he joined sixteen other young people at a village chapel, and from that humble origin sprang a spiritual revival that roared across the hills and valleys of Wales. Thousands of souls were welcomed into God's kingdom. Even the press could not ignore the changes occurring and eagerly reported on Roberts' every move. As suddenly as he had appeared, Roberts vanished from the world stage, only to reemerge twenty years later. What happened? How did God work so miraculously? Jessie Penn-Lewis was well-acquainted with the revival, and with its leader, Evan Roberts. Her clear and concise history of the events of that time remains a treasure for all those who pray for revival to return in our day.