Grosso - John Maria

Giovanni Maria Visconti inherited the duchy at age thirteen following the death of his father Gian Galeazzo in 1402, and his decade of rule was defined by spectacular misrule — contemporaries documented his habit of setting dogs on prisoners and his near-total indifference to governance. The duchy fractured badly during these years, with condottieri carving off territory almost at will.

He was murdered in 1412, stabbed outside a church in Milan, ending a reign unstable enough that coinage attribution to his name carries genuine historical weight. The MEC XII reference places this type firmly within the disrupted Milanese monetary sequence of the early fifteenth century.