The H was sometimes omitted in the fourteenth century.
“As wrtis [wortis] of erbis soone thei shul falle doun.” Wycliffite version of Psalm xxxvii. 2, (earlier version).
“Thei schulen falle doun soone as the wortis of eerbis.” Wycliffite version of Psalm xxxvii. 2, (later version).
But French words from Frankish, not Latin sources, take h, as hamlet, halbert, harass, hatchet; together with proper names, as Henry, Hubert. So also harness, a French word, but not of Latin origin.
Latin—The h is commonly sounded, as horrid. But honorary and honorarium follow the French word honour, and commonly omit h.
Greek—The h is important, as in history, hexagon, and should be sounded.
(2.) Accent.
Accent often drowns the h. Thus history takes h, but historical is usually istorical. To find this out, do not go by what people say they say (which is one thing), but by what you hear them say, which is a very different matter. Compare hebdomadal, hallucination, hereditary, hiatus, histrionical, hippopotamus, hexameter, hieroglyphic, histology, horizon, hidalgo, homœopathy, horticulturist; in all these, the h is very weak.
(3.) Rapidity.
Very common English words, as have, here, has, him, her, his, are pronounced ’ave, ’ere, in rapid speech. This will be denied stoutly by many who do so every day of their lives, especially in particular combinations. Much depends on the position of the word or the accent.