El Halcon is a prequel series to Nanatsu no Umi Nanatsu no Sora. Set from 1581 to 1586 with flashbacks further into the past, this is the story of Tyrian Persimmon. Born to a Spanish mother with an English husband in this era of conflict between the two contries, Tyrian favors Spain. His father suspects that Tyrian is not his son because he doesn’t look like the man at all, and regularly beats him. His mother’s lover is discovered to be a Spanish spy and flees the country. Tyrian is determined to join the navy and eventually rejoin Geraldo.
At the age of 19 he begins to make his ruthless way up the ranks of the English navy. (Translated Treasures)