The parts, which have come out blackish close to the river are yellow ochre in the original. The dark groups of houses inside the town are red. At the four points of the compass drawn in the middle of the town Leonardo has written (from right to left): Mezzodi (South) at the top; to the left Scirocho (South east), levante (East), Greco (North East), Septantrione (North), Maesstro (North West), ponente (West) Libecco (South West). The arch in which the plan is drawn is, in the original, 42 centimetres across.
At the beginning of October 1502 Cesare Borgia was shut up in Imola by a sudden revolt of the Condottieri, and it was some weeks before he could release himself from this state of siege (see Gregorovius, Geschichte der Stadt Rom im Mittelalter, Vol. VII, Book XIII, 5, 5).
Besides