Penn defended and fought for the right to publically preach since it was illegal at the time. Penn wrote many articles and pieces on the matter explaining and defending the practice of Quakerism, but that was not enough. He traveled to other locations in Europe and preached Quakerism. The religion slowly began to gain more followers all over Europe. .
Penn later went back to England to reconnect with his parents but was rejected by his father once again. Since he was unable to make amends with his parents, he left and continued to spread Quakerism. As a result of his actions and publications, he was tossed into the tower of London. The main reason this punishment was handed down to Penn was because of the book he published A Sandy Foundation Shaken. This book opposed the ideas and beliefs of the Doctrine of Trinity which was followed by most of Great Brittan.4 His sentence was life in prison. Mean while in prison, William Penn continued to write about his views and beliefs. He published one of his most famous books No Cross, No Crown. A little while later in 1668 Penn was released with the help of the Royal Chaplains; he had spent nine months in prison. Despite the fact that he was just released from prison for illegally preaching to an audience, he was determined to spread the word. .
In the year 1670, while Penn was across the sea, he received word of his father's death. The passing of his father left Penn a huge sum of money. This was money that the King owed his father for his services. During his travels he met Gulielma Springett who happened to be the step daughter of Isaac Pennington, a former acquaintance. Penn and Gulielma courted four years prior to their wedding on April 4th, 16725. Shorty after marriage they started their family and had a total of eight children. After many years of fighting for the right to practice his religion, Penn grew tired of being punished for following his beliefs.