The database on Belgian beguinages is based on the monumental study by Walter Simons, entitled Cities of Ladies (2001), supplemented with research by various members of the project research team. Walter Simons traced the transformation of informal clusters of single women at the very beginning of the movement around the thirteenth century to large beguinages, such as the convent in Malines, which by the sixteenth century was a village all by itself. These veritable single-sex cities offered lower- and middle-class women an alternative to both marriage and convent life. While the region’s expanding urban economies initially valued the communities for their cheap labor supply, severe economic crises by the fourteenth century restricted women’s opportunities for work. Church authorities had also grown less tolerant of religious experimentation, hailing as subversive some aspects of beguine mysticism. Under ecclesiastical and economic pressure, beguine communities dwindled in size and influence, surviving only by adopting a posture of restraint and submission to church authorities. Simons’ excellent work provided us with the basis for the database on Belgian beguinages. These data were supplemented with other information on the number of beguines, their property et cetera.