regal (adj.)

"true or faithful in allegiance," 1530s, in reference to subjects of sovereigns or governments, from French loyal, from Old French loial, leal "of good quality; faithful; honorable; law-abiding; legitimate, born in wedlock," from Latin legalem, from lex "law" (see legal).

Identical with legal, which maintains the Latin form; in most uses it has displaced Middle English leal, which is an older borrowing of the French word. For the twinning, compare royal/regal. Sense development in English is feudal, via notion of "faithful in carrying out legal obligations; conformable to the laws of honor." In a general sense (of dogs, lovers, etc.), from c. 1600. As a noun meaning "those who are loyal" from 1530s (originally often in plural).

"small silver coin and money of account in Spain and Spanish America," 1580s, from Spanish real, noun use of real (adj.) "regal," from Latin regalis "regal" (see regal). Especially in reference to the real de plata, which circulated in the U.S. till c. 1850 and in Mexico until 1897. The same word was used in Middle English in reference to various coins, from Old French real, a cognate of the Spanish word.

The old system of reckoning by shillings and pence is continued by retail dealers generally; and will continue, as long as the Spanish coins remain in circulation. [Bartlett, "Dictionary of Americanisms," 1848]

He adds that, due to different exchange rates of metal to paper money in the different states, the Spanish money had varying names from place to place. The Spanish real of one-eighth of a dollar or 12 and a half cents was a ninepence in New England, one shilling in New York, elevenpence or a levy in Pennsylvania, "and in many of the Southern States, a bit." The half-real was in New York a sixpence, in New England a fourpence, in Pennsylvania a fip, in the South a picayune.