How many starships called Enterprise?

[Lord Pounder]

The Enterprise A was destroyed in a battle with the New C&C of starfleet. The A died fighting off a Klingon Battle Cruiser in the Corona of a sun. I'm not sure if thats cannon though as it happened in the book The Ashes Of Eden.

[Enola Straight]

According to the ST Encyclopedia, an early spacecraft called the S.S. Enterprise was one of the first ships to bear the name.

Looks like two ring-shaped nacelles surrounding a central rod-shaped module...similar to ENTERPRISE era Vulcan ships.

[Gil Hamilton]

Well, the obvious reason behind the disparity is that as of TNG, the Akiraprise didn't exist in the franchise, they didn't plan on it or take it into account, thus it wasn't mentioned than the E-nil was the first starship launched by men to bear the name Enterprise. Then ole B&B said "Hey, let's make a new Enterprise!" so they did, not carrying about continuity but rather marketability, since Enterprise is a highly recognisable name.

[The Dark]

Pre-Starfleet and the federation there where earth bound sea ships called Enterprise. Remember the Nuclear Wessles incident.

Over twenty:

1705: British Fifth Rate sailing ship
1709: British Sixth Rate
1730: British Sloop
1738: British Passenger ship
1743: British Sloop
1759: French Frigate
1774: British Sixth Rate
1775: American Sloop
1776: American Privateer
1799: American Schooner
1831: American Schooner
1864: British Sloop
1877: American Sloop
1914: American Motorboat 790
1914: British Light Cruiser
1930: American Racing Yacht
1936: American Aircraft Carrier CV-6
1959: British Inshore Survey Ship A-71
1961: American Aircraft Carrier CVN-65
1976: American Racing Yacht
1981: Barbados Patrol Craft P-02

There have also been terrestrial aircraft named Enterprise:
1861: American Balloon
1935: American Training Airship L-5
1946: American Blimp
1976: American Space Shuttle OV-101
1979: Goodyear Blimp GZ-20

[Stormbringer]

I'm still puzzled as to why Starfleet would upgrade their Constitution fleet only to turn around and deem them obsolete in a few scant years.

IIRC, the non-canon origin of the E-A was that it was originally the Yorktown but was renamed. (wonder how long it takes to paint the ships...)

Fleet draw-down after Khitomer. You decom the ships that are oldest first when reducing fleet size, even if you did give them SLEP--though of course any ships around which were still of similiar technology to the original Constitution-class would have gone first, but maybe Starfleet's budget was really enough to handle the whole fleet back then.

There might have been retirements we don't know about. Surely the Federation has ships other than the Constitutions, and it might even include unrefitted Constitutions.

As for the Mirandas, if you assume that the Mirandas were newly built at the time the Connies were retired it might just be that they were as modern as they needed to be. The Constitutions were a front line vessel where as the Mirandas were not, at least ideally.

[Drooling Iguana]

According to the ST Encyclopedia, an early spacecraft called the S.S. Enterprise was one of the first ships to bear the name.

Looks like two ring-shaped nacelles surrounding a central rod-shaped module...similar to ENTERPRISE era Vulcan ships.

That was shown in the background in TMP and, I believe, in the 2nd season Enterprise episode "First Flight" (I saw something that looked like it in a picture in the background of the bar set, although I didn't get a good look at it.)

[Trogdor]

The continuity breach is easily explained: B&B don't give a damn about continuity and assumed that if they named the NX-01 "Enterprise" then people would magically like it because it's named Enterprise!
Idiots