What should come first in HTML, an anchor or a header? [duplicate]

Answer 1

From a semantic perspective: both (or neither).

(From a structural perspective, OTOH, before HTML 5 an anchor cannot contain a heading, and since browsers aren't all HTML 5 capable yet you should avoid the new form of the construct where possible)

If you are creating a link target, then

is preferred to

anyway.

If you are creating a hyperlink, then having the most important heading on the page link somewhere else is somewhat dubious from a semantic point of view.