Short answers, pulled from the story.
The name Canary Islands comes from the Latin word canis, meaning dog, not from the small yellow birds that now bear their name. Ancient Roman historians described the islands as the Islands of the Dogs because they were home to vast multitudes of large dogs and possibly monk seals called sea dogs.
The Castilian conquest of the Canary Islands began in 1402 with the expedition of Jean de Béthencourt and Gadifer de la Salle. The final subjugation of Tenerife and La Palma occurred in 1496 by Alonso Fernández de Lugo, bringing the entire archipelago under the control of the Crown of Castile.
Mount Teide on Tenerife is the highest mountain in Spain and the third tallest volcano on Earth on a volcanic ocean island. The island chain's most recent eruption occurred at Cumbre Vieja on La Palma on the 19th of September 2021.
The Canary Islands are visited each year by about 12 million people. Tenerife has the largest number of tourists received annually, followed by Gran Canaria and Lanzarote.
The Tenerife airport disaster occurred on the 27th of March 1977, when two Boeing 747s collided. This event killed 583 people and remains the worst air disaster in the history of aviation.
El Hierro has 10,798 inhabitants and covers 268.71 square kilometers. The whole island was declared a Reserve of the Biosphere in 2000.