A maritime exhibition in a museum of archaeology might not be the most obvious place to find a silver stirrup.
However this was part of the exhibition of maritime archaeology at Lisbon’s Archaeological Museum

Silver stirrup with shell decoration

18th Century silver stirrup from shipwreck

It is catalogued as a silver stirrup dating from the 18th century, measuring 14cm x 12.5cm x 9.7cm and weighing 667grams.

It was the first object which identified the archaeological site of the wreck of the San Pedro de Alcantara.

Silver stirrup from shipwreck

18th century silver stirrup

The stirrup is heavily decorated. There is a suspension loop, the sides of the arch have masks at their top ends these have beards which flow down the flared sides of the arch. The front of the stirrup is protected by two shells making it a “cage stirrup” ( or in portuguese “de janela” or window stirrup ).
It was made in Peru, then a Spanish possession. Shells were frequently used in the baroque style of decoration and the fashion for the baroque lasted around a century longer in Peru than in Spain.
However, scallop shells also frequently appeared on harness decorations – a reference to the pilgrimage to Santiago de Compostela. There were one hundred licensed scallop shell sellers around the cathedral of Santiago in 1200AD, it may be that the shell refers back to an earlier pre-Christian religious ritual around the journey of the dead, read more here

It seems rather ironic that a stirrup with a maritime theme should end up in a famous shipwreck.

Pillemont painting of the wreck of the San Pedro de Alcantara
The wreck of the San Pedro de Alcantara by Jean-Baptiste Pillement

The San Pedro de Alacantara was a ship of the line of the Royal Spanish Navy. It was built in Cuba and launched in 1771. The ship was a prototype and there were problems with its design.
It was active in the Pacific Ocean during the American Revolutionary war, when Spain also declared war against Britain in 1779.
In 1783 it set sail for Cadiz in Spain from the port of Callao, very heavily laden with gold, copper, ancient pottery and prisoners from the Tupac Amaru Inca rebellion. It seems that the ship may have been overloaded with heavy cargo , partly because of the end of the American War of Indepence, partly because the British had finally lifted the blockades on South American ports and partly because of the Inca rebellion. It had to stop en route to Spain for repairs and eventually was wrecked at 10.30pm on February 2nd 1786 at Peniche, north of Lisbon.
One hundred and fifty two people died in the wreck including seventeen Tupac Amaru rebellion prisoners who were still manacled at the time, fourteen officers, five women and one hundred and twenty eight crew members. Shortly after the wreck many divers arrived from all over Europe to salvage valuables, they retrieved most of the guns and a large quantity of gold and copper ….

but not this one piece of silver, which stayed submerged for another two hundred or so years