The Imperial Constitution campaign was an initiative driven by radical democratic politicians in Germany in the mid-19th century that developed into the civil warlike fighting in several German states known also as the May Uprisings (Maiaufstände). These conflicts against the counter-revolutionaries began in May 1849 and varied in length and intensity depending on the region. Some lasted until July that year. They marked the end phase of the popular and nationalist March Revolution that had started in March 1848.