I looked into this word a while back, and, largely with the assistance of a trusty friend, my trusty unabridged OED (I love it! An absolute a treasure trove!), and the works of Shakespeare, we came up with the following. It was produced for a purpose other than this, and I've modified it so that it will more or less work as a node :) (let me know if it's in anyway not right...)

The verb "hector" {from sense 2 of the noun "hector", as referenced in the 1927 ed. of the OED}

1) (intransitive) To play the hector or bully; to brag, bluster, domineer. 1660 Hickeringill in Jamaica: "For which he needs not venture life nor limb, Nor Hector it, nor list under Sir Hugh." 1681: "While I hector and rant and call names." 1723 Swift in Stella at Wood Park: "Don Carlos made her chiefe director, that she might o'er the servants hector."

2) (transitive) To intimidate by bluster or threats; to domineer over; to bully; to bring or force out of or _into_ something by threats or insolence. 1664 Pepys Diary "Our King did openly say... that he would not be hectored out of his right and preeminencys by the King of France." 1670 Dryden Conquering Grenada "But fortune she's a drudge, when hector'd by the Brave."

The noun "hector" {from the latin Hectör, from the greek Hector son of Priam and Hecuba, husband of Andromache, 'the prop and stay of Troy.' The greek name "Hector" is derived from the Greek adjective "holding fast" in turn derived from the greek verb "to have, hold."

1) The name of a Trojan hero celebrated in the Illiad; a valiant warrior like Hector. 1387 Trevisa in Higen "if we will mean þat þey beeþ... hardy, we clepeþ hem _Hectores_" if we want him to be hardy, we will call him by the name of _Hectores_ 1598 Shakespeare in The Merry Wives of Windsor "Said I well, bully hector?"

2) (contraction of the common idiomatic expression "bully hector" see the notes about "bully" below.) A swaggering fellow; a swashbuckler; a braggart, blusterer, bully. 1655 Sir E. Nicholas in (a newspaper) "The Earl of Anglesie and his two Hectors upon Sunday morning last fought a duel with..." 1693 Luttrel in (another newspaper) "On Sunday night last, three hectors came out of a tavern in Holbourne with their swords drawn, and began to break windows." (was Sunday at one time meant to be a day of mischief? One wonders.)

3) The name of a species of flutterby (that would be a "butterfly" for any traditionalists in audience :).
To discuss "bully" as it relates to "hector":

One of the earlier meanings of "bully" seems to be important to an understanding of the etymology of "hector" in its pejorative sense. "Bully" is of indistinct etymology, but it is likely related to Dutch and German words used to describe a "lover" (regardless of gender). Initialy used in old English as a term of endearment suitable for one's lover, regardless of gender. It shortly came to be used only to refer to a male lover (I gather the gender of the lovee was distinctly unfixed here; it is at this stage that "ambiguous" undertones attach to the word) that one would probably not want to tell one's mother about. Just prior to Shakespeare, the meaning is influenced by the Scottish word "billie" which means "brother," and its meaning forks. On one hand we have it used as an endearment for a perhaps somewhat exciting friend, thence an admirable companion or worthy buddy, and thence expressions like "bully for you," and on the other hand we have it used to mean the protector of a prostitute (a kind of lover/brother,) thence a ruffian, thence a noisy, hired ruffian, thence a noisy hired ruffian wannabe, a.k.a a schoolyard bully. Upon reading the Shakespearean uses, called him "bully hector" so Hector must have been a bully too!

The clearest thing about the etymology of "bully" is that it has nothing whatsoever to do with "bull" as in a male bovine or any of it's byproducts. The connsonance of the two words, however, is apparently a contributing factor to the bad rep bulls have to put up with, deservedly or not.

And so the expression "bully hector" came to mean an admittedly strong person who was given to "bully" people.