The H in the name of the metal is derived from the F of Latin ferrum (compare higo for 'fig'), a phonetic mutation that was complete by the end of the Middle Ages.

As early as the 16th century, maps and texts called the island after the word for 'iron' in other languages: Portuguese Ferro, French l'île de Fer,[4] and Latin Insula Ferri.

Juan de Abreu Galindo (in a manuscript translated and published by George Glas in 1764) gives the native name of the island as Esero (or Eseró), meaning 'strong'.

[5] Richard Henry Major, however, in notes on his translation of Le Canarien, observes that the Guanche word hero or herro, meaning 'cistern', could easily have lapsed into hierro by a process of folk etymology.

The ancient natives of the island, called Bimbaches, were subjected to Spanish rule by Jean de Béthencourt (d.1425) – more by the process of negotiation than by military action.

[14] On 11 October the volcanic threat level at La Restinga was raised from "yellow" to "red" after minor rockfalls on the slopes above the town.

[26] The non-barren parts of the interior rely on relief precipitation, not much more than the average of 19 rainfall days per year, high relative humidity and geothermal springs.

[32] With continued activity resulting in the island expanding to have the largest number of volcanoes in the Canaries (over 500 cones, another 300 covered by more recent deposits), together with approximately 70 caves and volcanic galleries, including the Cueva de Don Justo whose collection of channels exceeds 6 km.

The island is part of the province of Santa Cruz de Tenerife, and includes three municipalities: Valverde is situated in the northeast and Frontera in the west, both contain several villages.

By the 2nd century CE, Ptolemy already considered a definition of the zero meridian based on the westernmost piece of land in the (known) world, giving a few maps with only positive, eastern longitudes.

Flores Island is the westernmost Azore discovered by the Portuguese navigators in the early 15th century—after the First Voyage of Columbus in 1492 scholars and cartographers sometimes grouped them among the new world.

During the festival, the Virgin of the Kings (Virgen de los Reyes, patron saint of the island of El Hierro) is taken from her sanctuary in La Dehesa (in the municipality of La Frontera) and carried to the capital of the island, Valverde, making a tour of 44 kilometres and running through all the towns of El Hierro.

[44] According to the Ministry for Industry, Tourism and Commerce, El Hierro hopes to become the first island in the world to be self-sufficient for electrical energy.

[45][46][47][48] This hydro and wind-power project, created by the local Gorona del Viento El Hierro consortium with financial aid from the European Union, and officially inaugurated in 2015, consists of five E-70 wind turbines capable of producing 11.5 megawatts of wind power to supply electricity for approximately 11,000 residents, an additional number of tourists, and three water desalination facilities.

The hybrid wind/pumped hydro storage system stores surplus wind power by pumping water up 700 metres (approximately 2,300 feet) to the crater of an extinct volcano.

When winds are calm or when demand exceeds supply, water is released from the crater to generate 11.3 MW of electricity, filling a smaller artificial basin created at the bottom of the extinct volcano.

The festival is a contribution of the international artist community to El Hierro's "Sustainable Island" program and collaborates with scientists and sustainability-oriented organizations from around the world.