Originally Posted by BookCat
It's available at Project Gutenberg, so yes, it's in the public domain. I hope someone capable of doing a good job of formatting to epub can upload one for you, unfortunately, it's beyond me.
Just realised I found it on the Canadian PG, not sure where you are or if the rules are the same in your country. The link, for anyone who can convert it, is:
Lytton Strachey died in 1932 so his works should be PD in Life+50 and Life+70 countries. Elizabeth and Essex
was published in 1928 making it potentially (if renewal was properly filed) still under copyright in the US. PG/US has his earlier works but not this one making it very likely that the US copyright is still in effect.