Lady Fanny Lucy Houston, a former Cockney chorus girl known as 'Poppy'
Radmall, became the fifth woman in the realm to receive the DBE in
1919, in recognition of her having opened a home for tired nurses.
(She was then Lady Byron).

Who were the first four recipients and why were they recognised?

Good Morning, probonopublico!

Thank you for an interesting question to start my day.

In 1917, Katharine Furse was made a Dame of the Empire for her
services as the head of the VAD (Voluntary Aid Detachment) nursing
system.  You will find a capsule biography at this link:
http://www.ku.edu/~kansite/ww_one/bio/f/furse.html

In 1918, the Australian-born operatic diva Nellie Melba (Helen Porter
Mitchell) was honoured as a DBE in recognition of her pre-eminence in
music.  A brief bio on a site dedicated to famous Aussies:
http://www.awm.gov.au/forging/australians/melba.htm

Also in 1918, actress May Whitty was made a Dame. She had up to this
time been primarily a stage actress, but made the transition to film
remarkably well.  For a look at her in her best-known film roles, see
the Greer Garson vehicle "Mrs. Miniver" or her own starring turn in
Hitchcock's "The Lady Vanishes".  A capsule bio of Dame May is located
at this link:
http://www.slider.com/enc/56000/Whitty_Dame_May.htm

Her entry in the Internet Movie Database is found here:
http://us.imdb.com/Name?Whitty,+Dame+May

The fourth pioneer has been much harder to track down.  The likeliest
candidate seems to be Australian WWI nurse Alice Chisholm, subject of
the book "Lady of Kantara: A biography of Dame Alice Chisholm
1856-1954" by Janet Maxwell Champion.  Here at a Chisholm family
geneology site, we find a summary of the book:

"NOTE: Dame Alice Chisholm served in Egypt and Palestine during the
First World War, receiving the decoration of 'Dame of the British
Empire' for the work she did setting up canteens for the men." This is
the link:
http://www.clanchisholmsociety.org/Pages/Australia-ChisholmBib.html

A portrait of Chisholm during the war is at this link:
http://www.awm.gov.au/forging/ww1/lambert.htm

A rival claimant may be Dame Margaret C. MacDonald of Nova Scotia,
Canada.  Matron-in-Chief of the Canadian Army Nursing Services, she
served in the Boer War and WWI.  Like Chisholm, she was made a DBE
during the appropriate timeframe but no on-line source gives the date
of her elevation.  This link at St. Francis Xavier University gives a
one-paragraph bio (see paragraph 8):
http://www.stfx.ca/people/lstanley/Cultural/didyouknow.htm

Further information from Trent University:
http://www.trentu.ca/library/archives/fnursesandww1.htm

MacDonald and others at the inauguration of the Nursing Sisters'
Memorial:
http://www.vac-acc.gc.ca/general/sub.cfm?source=memorials/memcan/memnurse

Finally, pioneering astrophysicist Margaret Lindsay Huggins may have
been the fourth, since she died in 1915 and is referred to as "Dame
Margaret".  However, this may be due to her marriage to Sir William
Huggins, KCB.  In any case, her contributions to the science certainly
WOULD have merited a DBE in her own right.

I hope this is satisfactory.  If any of my colleagues are able to
confirm the fourth DBE from offline sources, I am certainly open to
correction or clarification.

Search strategy:

+"Dame of the British Empire" +first  (main search)

I also searched on the names of each of the women above individually,
which yielded additional information in most cases.

An e-mail to ST. F. X. university might confirm the date of
MacDonald's elevation, while e-mailing the Chisholm geneology page
should do the same for Dame Alice.

Thank you again for lending some interest to my morning!

-Chromedome

Brilliant! And so quick! I would actually prefer to give you 20 Stars
but I don't know how. Perhaps you can help me?