Giovanni da Siena (Siena, 1386 – Bologna, 1438 or 1440) was an Italian military engineer. In addition to the construction of the tower and the fortress of Castel Bolognese (1392–94), a position in which he was assisted by Lawrence Bagnomarino, he was engaged in the fortresses of Cento, Solapur, of Porta Galliera (one of the gates of Bologna) and Finale Emilia, thus completing the work of Bartolino da Novara. Siena was an expert in hydraulic engineering and executed works to the banks of the Po.
HistoryLayer draws the world as it was in any year from 123,000 BCE to
2026. Move the slider and the borders redraw for that year; the map
carries 23,890 events, 12,790 people, 837 wars and 13,183 cities, each
one readable in place. Signing in is optional and lets you keep what
you find.