Bellinzona: castles, customs and the Confederate advance

The barrier of the valleys

Bellinzona occupies the point at which the valleys of the Ticino and the Moesa meet and the valley floor narrows between steep mountain slopes. Whoever held it controlled the roads from the Gotthard, the Lucomagno and the San Bernardino towards Lake Maggiore and the Monte Ceneri. The Visconti, who took the town in 1340, turned it together with their Sforza successors into a fortress of European rank.¹ Its three castles, Castelgrande on the rocky hill above the town, Montebello on the eastern slope and Sasso Corbaro higher up the same slope, were linked by walls to the fortified town. A great wall, the Murata, ran across the whole valley floor from Castelgrande to the river Ticino, so that no traveller, merchant or army could pass without entering the fortress.²

The fortifications are today listed by UNESCO as a World Heritage site under the name "Three Castles, Defensive Wall and Ramparts of the Market-Town of Bellinzona".³ The designation is apt. Bellinzona was at once a castle, a customs post and a market town, three functions that reinforced one another. The castles protected the market, the market attracted the merchants whose goods paid the toll, while the toll financed the garrison. For the Milanese dukes the fortress was the northern gate of their state, which they maintained at considerable expense because the alternative was an open road for Confederate armies.

Building the fortress

Castelgrande is the oldest of the three castles. Its hill was fortified in late Roman times. The medieval castle was developed by the bishops of Como and their vassals before the Visconti extended it.⁴ Montebello was built in the thirteenth and fourteenth centuries, in part by the Rusca, and was enlarged and linked to the town walls under the Visconti. Sasso Corbaro, the highest and most isolated of the three, was built after the Milanese defeat at Giornico in 1478, when the Sforza realized that the fortress needed an outwork capable of resisting artillery on the eastern slope. It was erected in great haste in 1479.⁵

The Murata was rebuilt in its final form in the 1480s under Ludovico il Moro. It ended at the river in a fortified bridge, the Torretta, which carried the road across the Ticino and closed the valley on its western side. On 20 May 1515 the collapse of a natural dam in the Blenio valley, the Buzza di Biasca, sent a flood wave down the Riviera that destroyed the bridge at Bellinzona.⁶ The catastrophe was recorded in a woodcut published in 1548 and remained in the regional memory for centuries.⁷ By then Bellinzona already belonged to the Confederates, and the section of the Murata destroyed by the flood was never rebuilt.

Notes

1. DSS, art. "Bellinzona (comune)" (above). ↩
2. DSS, art. "Bellinzona (comune)" (above), on the Murata built across the whole valley in the second half of the fourteenth century. ↩
3. Wikipedia, "Castles of Bellinzona", https://en.wikipedia.org/wiki/Castles_of_Bellinzona (consulted as a last resort), on the inscription in 2000; UNESCO World Heritage Centre, list entry 884, https://whc.unesco.org/en/list/884/. ↩
4. DSS, art. "Bellinzona (comune)" (above), on the late Roman wall, the transfer to the bishop of Como in 1002/1004 and Montebello as a Rusca castle of the late thirteenth century. ↩
5. DSS, art. "Bellinzona (comune)" (above). ↩
6. DSS, art. "Buzza di Biasca", https://hls-dhs-dss.ch/it/articles/028662/ (landslide of 30 September 1513, dam break of 20 May 1515, destruction of the Torretta bridge built in 1487); see also "20 maggio 1515: la 'Buzza' che impressionò l'Europa", SUPSI, ARIS repository, https://aris.supsi.ch/entities/publication/2e9868d3-cc92-44f4-9915-ddf146491cea. ↩
7. La nostra storia, "La Buzza di Biasca distrugge il ponte della Torretta a Bellinzona - Silografia del 1548", https://lanostrastoria.ch/entries/Zb67g0Q9XrM (title only consulted, 27 September 2026); Wikipedia, "Castles of Bellinzona" (above), on the part of the Murata destroyed in 1515 and never repaired. ↩

For general information only. This article does not constitute legal or tax advice, does not replace advice on an individual case and creates no lawyer-client relationship. It reflects the legal position as of August 2025.