Dance Forms: What are Hornpipes?

One of the oldest of the dance forms from western Europe/Great Britain are the Hornpipes.  

Here are some of the Hornpipes I like

There are two basic types of common-time hornpipe, ones like the "Sailors' Hornpipe", moving in even notes, sometimes notated in 2/2, moving a little slower than a reel, and ones like "The Harvest Home", moving in dotted notes. Some 19th-century examples mix the dotted and even styles.  (Other types of Hornpipes are in 3/2 and 9/8 time.)

Examples of Hornpipes:

Fisher's Hornpipe