Famiglie di Firenze
Marriage in medieval times was a method of ensuring alliances, and the social network of wealthy families of Florence in the 15th century has been the focus of many investigations of medieval history. These pictures show the marriage relationships between these families.
The most prominent family was the Medici, the large node in the second top row and the second column from the left. The Medici intermarried with many other families. They formed a tight clique with the Ridolfi and Tornaboun families and came to control most of the commerce and politics in Florence (and indeed Rome), either directly or through alliances with other families. In contrast, the Pucci family (at the bottom right) had no marriage connections. The Pucci lacked power, and in the 16th century they were exiled.
Each of these pictures uses a straight-line planar layout. The straight-line edges are adjusted slightly by adding two control points to each edge and rendering using cubic Bezier curves. The network has two marriage cliques that are shown by a (weighted) Voronoi tessellation in the background. The central red cluster in (b) is the Medici-Ridolfi-Tornaboun clique; the other clique (centred on the Strozzi family) is in green at the bottom right. Nodes size is proportional to the logarithm of the number of marriage connections.