Annular solar eclipses occur when the moon passes directly between the earth and the sun, but is far enough away from the earth that its angular size does not quite cover the entire solar disk, and a very thin ring of sunlight is observed.
Annular solar eclipses were portrayed on coins with an annulet. But not all annulets on coins are eclipses. Annulets also represented the sun or the moon, or were simply a die engraver's or mint mark, or purely a decorative device. But as early as 700-550 BC, an annulet can be found along with a crescent on the reverse of a triobol of Aegina. Clearly, the crescent represents either the moon or a partial solar eclipse, and thus, the annulet probably represents a celestial body as well.
In 1290, Edward II, Crown Prince of England, was named as the count of the French province of Ponthieu, upon the death of his mother, Eleanor of Castile. But his title was contested by the Count of Alencon. The only coinage of Ponthieu during the rule of Edward prior to his becoming king has a unique design consisting of crescents and annulets.
On the 5th of September 1290, during the first year of his reign as count, an annular solar eclipse crossed directly over southern England and northern Europe, including the province of Ponthieu. Did Edward II use this celestial event as an omen for his right to authority?
The written record documents that this annular eclipse was observed. In Limoge, France, Godel (c.1320) wrote: "Also in this year , on the day of Mars, before the Nativity of the Blessed Mary, in the first hour, with the moon at the 27th, there was an eclipse of the sun, with the sun itself being in Virgo, in the time of Pope Nicholas III. The partial and annular phases of the eclipse must have appeared similar to the figure shown above. Notice the similarity to the coinage design.
Prior to this coin of Edward II, Ponthieu deniers of Jean de Nesle (1251-1279) and Gillaume III (1191-1221) did not contain annulets, but those of Gui I (1053-1100) and Jean I (1147-1191) did. From 1147 until the English inheritance in 1279, only one annular eclipse (26 October 1147) was visible from Ponthieu or nearby regions, which coincided with the accession of Jean I as count. One of the deniers of Gui I had alternating annulets and crescents. Nearby annular eclipses of 1084 and 1093 may have been depicted. Thus, besides taking the 1279 eclipse as an omen, Edward II also followed the local custom and coinage design.