The political role of cities in helping state formation—and in staying independent—is the theme of Charles Tilly and W. P. Blockmans, eds., "Cities and the Rise of States in Europe, A.D. 1000 to 1800" (1994). Comparative elite studies—who was in power—are typified by Luisa Passerini, Dawn Lyon, Enrica Capussotti and Ioanna Laliotou, eds. "Who Ran the Cities? City Elites and Urban Power Structures in Europe and North America, 1750-1940" (2008) . Labor activists and socialists often had national or international networks that circulated ideas and tactics.