From Reviews (ADR) by Arthur D. Rypinski:
In the spring of 1860, the 58-year-old Alexandre Dumas purchased and fitted
out a large sailing yacht, the "Emma," for a projected voyage to the
classical sites of the Eastern Mediterranean and the Holy Land. He took
with him captain, cook, crew, several young companions, and his youthful
mistress, Emilie Cordier, who affected a midshipman's uniform for the trip.
Naturally, Dumas contracted with the Paris Journal "Le Constitutionnel"
for a series of articles.
Dumas sailed from Marseilles to Genoa, where he had some business: to edit
the "Memoires" of his friend General Giuseppe Garibaldi, the hero of the
Italian "risorgimento." The Italian Peninsula was, at this time, divided
into numerous statelets and partially occupied by foreign powers. King
Victor Emmanuel, starting from a nucleus of Sardinia and Piedmont, was
gradually assembling an Italian state from the pieces, in a series of wars
and negotiations. Garibaldi provided some of the military muscle and much
of the moral inspiration.
Dumas found that Garibaldi was not in Genoa. While Dumas was at sea, an
insurrection had broken out in Palermo, at that time part of the Bourbon
Kingdom of Naples, which held the southern end of the Italian "boot."
Garibaldi had submitted his resignation to King Victor Emmanuel, (to
preserve "plausible deniability") raised and armed a thousand volunteers,
commandeered two steamers at gunpoint, and headed south with his "thousand"
for Sicily.
Naturally, Dumas instantly changed his plans, and sailed for Palermo.
However, Dumas' publisher, who had contracted for a travelogue rather than
an anti-monarchist insurrection, dropped Dumas. Dumas promptly contracted
with another journal, "La Presse" for a series of reports on the
revolution.
Dumas, however, did a great deal more than just file reports. He arranged
for the purchase (in France) of munitions, and their shipment to the
insurgents. He anchored his yacht in Naples harbor, a "half pistol shot"
from the King's Palace, and set up shop as a full-service covert operator,
encompassing black propaganda, suborning cabinet ministers and police,
bribing mercenaries to desert with their weapons, providing tactical
intelligence of troop movements and arms to local guerillas, and strategic
intelligence on King Francis II intentions to Garibaldi.
Dumas published the war letters from "La Presse" in book form as "Les
Garibaldiens: Revolution de Sicile et de Naples" in 1861. Subsequently,
he combined the travel letters from the beginning of his trip with the war
letters from end, and added some additional "now it can be told" material
to form a combined manuscript covering the entire trip. This combined
manuscript was not published. Much later, the manuscript was identified by
Dumas scholar Robert Garnett, translated into English, and published (in
1929) as "On Board the Emma."
From A Bibliography of Alexandre Dumas père by Frank Wild Reed: This has been aptly called the first book of the modern war correspondent. It is a vivid and interesting narrative of Garibaldi's Sicilian adventure, drawn in part from the accounts of participants in the events, and the rest is based on the author's personal observations and experiences. Dumas was on his way to tour the eastern Mediterranean in his yacht, the "Emma," when he heard of Garibaldi's landing in Sicily. He immediately proceeded there, gave up his plans, and, for four years, devoted himself whole-heartedly to the cause of the general and a united Italy.
Quite recently the original MS. of this work was purchased by Mr. R. S. Garnett. It proved to contain much matter not in the original edition, in fact, fully two-fifths of the whole are quite new. However, the scarce fourth volume of Dumas' journal "Le Monte-Cristo," that for 1862, was discovered to contain the whole of this narrative, save for a few pages which had not been printed when the publication ceased. The work was there entitled "Une Odyssée en 1860."
Mr. Trevelyan points out that the critics, who have been inclined to belittle this work, did Dumas much injustice.
In the "Monte-Cristo" text Dumas has intercalated the material of the four "Causeries" entitled "Comment je mis Garibaldi" (refer to page 384). Many small variations are to be found between the MS, and the publication in the journal. There are also not a few re-arrangements of both whole chapters and lesser portions. By comparing these fuller accounts with the much abridged work in the standard collection, still further modifications are quickly discoverable.
Original edition : Paris, Michel Lévy Frères, 1 vol., 12mo., 1861.
It now fills one volume in the standard Calmann-Lévy series. In Le Vasseur's "Alexandre Dumas Illustré" it forms part of Vol. XXIV.
References :— Glinel: "Alex. Dumas et Son Gouvre," page 459. Parran: "Bibliographie d'Alexandre Dumas," page 67.
Trevelyan: "Garibaldi and the Thousand " and "Garibaldi and the Making of Italy."
English Translations :—
"The Garibaldians in Sicily;" London, Routledge, pp. 186, 1861.
"On Board the 'Emma," Adventures with Garibaldi's 'Thousand' in Sicily:" London, Benn, demy 8vo.. illustrations, facsimiles and map: translated, with appendices and introduction, by R. S. Garnett. pp. xvi., 387,1929