The Sun of May, which appears on the national flags of both Argentina and Uruguay, is so called in reference to the May Revolution of 18 to 25 May 1810, which marked the beginning of independence from the Spanish Empire for the countries that were then part of the Viceroyalty of the Río de la Plata. There is a legend that as the new government was proclaimed, the sun broke through the clouds; this was seen as a good omen.
The Sun of May was depicted on the first Argentinian coin, which was issued in 1813. It is said to be a representation of the Inca sun god Inti, but it bears distinct similarities to the common European heraldic symbol known as 'the sun in splendour' or 'the sun in his glory', which was adopted by both Edward II and Edward IV of England (among many others).
The sun in splendour consists of a yellow disc with a human face, and either twelve or sixteen rays. The rays alternate between straight and wavy; the straight rays are said to represent the sun's light, the wavy ones its heat.
The Sun of May, as depicted on the 1813 Argentinian coin, has 32 rays, alternating between straight and wavy as in the sun in splendour. The version on the Argentinian flag is very close to that on the coin, but the Uruguayan version has 16 rays instead of 32 (the eight straight rays appearing in front of the wavy ones).
Early Peruvian flags also showed the Sun of May (very similar to the Argentinian version, but in red with yellow detail) before the current red, white and red vertical triband was adopted in 1824.
© Haydn Thompson 2017