Helme church parish was first mentioned in 1329 during a Lithuanian raid. Most of the neighbouring land was fiefed in the 15th–16th centuries. Livonian Order castle in Helme (Ordensburg Helmet) was probably built in the first half of the 14th century. The site on a steep hill is belived to have been used as a stronghold earlier by Sackalians in the Ancient Estonia. By its ground plan the order castle was 120×60 m oval shaped structure, surrounded by two moats. There was a borough beside the castle in the Middle ages, it was mentioned until the 17th century. The castle was destroyed by the Swedes during the Russo-Swedish War in 1658. Nowadays only parts of the walls with high window holes have survived.
Sirmione castle was built near the end of the 12th century as part of a defensive network surrounding Verona. The castle was maintained and extended first as part of the Veronese protection against their rivals in Milan and later under the control of the Venetian inland empire. The massive fortress is totally surrounded by water and has an inner porch which houses a Roman and Medieval lapidary. From the drawbridge, a staircase leads to the walkways above the walls, providing a marvellous view of the harbour that once sheltered the Scaliger fleet. The doors were fitted with a variety of locking systems, including a drawbridge for horses, carriages and pedestrians, a metal grate and, more recently, double hinged doors. Venice conquered Sirmione in 1405, immediately adopting provisions to render the fortress even more secure, fortifying its outer walls and widening the harbour.
Thanks to its strategical geographical location as a border outpost, Sirmione became a crucial defence and control garrison for the ruling nobles, retaining this function until the 16th century, when its role was taken up by Peschiera del Garda.