In 1909, Mignault was granted a militia commission in the rank of surgeon lieutenant with the 65th Regiment "Carabiniers Mont-Royal" (now
Les Fusiliers Mont-Royal). which ensued in the creation of the
22nd Battalion, CEF Founding of French Canadian army units In 1914, Mignault communicated with Prime Minister
Robert Borden to propose the establishment of a solely
French Canadian battalion within the
Canadian Expeditionary Force (CEF). According to Mignault, this would allow Canadians of French extraction to circumvent the language barrier of the English-speaking battalions. To support his cause, Mignault offered the significant amount of C$50,000. He expressed the desire to accompany the unit overseas, should it be formed. Despite Canada's relatively modest population, Borden had recently committed his country into providing half a million soldiers for the
Allied cause. Realizing the difficulty of raising such an army on a voluntary basis, Borden conceded. Accordingly, on 14 October 1914, the exclusively French Canadian
22nd Battalion, CEF, was formed. Mignault proved himself right as his recruitment campaign turned out to be a considerable success. Through French Canadian newspapers and media hype, the ranks of the newly formed battalion were filled in less than a month. Shortly thereafter, content of his recent achievement, Mignault moved to personally finance two other French Canadian battalions, the
41st and the
57th. However, these two lesser-known units fell short of experienced French Canadian officers: most of them had already been moved from English-speaking units to the 22nd Battalion.
Overseas While Mignault soon realized that he would not be put in charge of a battalion by financing infantry units, as such was clearly his desire, he opted to found and finance a medical unit. By early spring 1915, Mignault had encouraged the Canadian government to settle down a solely French Canadian stationary hospital near the German frontlines in eastern France. He argued that such an establishment could improve Canadian medical implication on the
Western Front, as French-speaking medical personnel would naturally better fit, within French lines, than their English counterparts. The government recognized the need to improve Canada's medical efficiency in France. The fourth Canadian Stationary Hospital would soon commence its recruitment campaign. Mignault was put in command, and was promoted to the rank of lieutenant colonel. By November 1915, Mignault, along with 100 men, had reached the commune of
Saint-Cloud in suburban Paris, where the hospital would be deployed. On 15 April 1916, a month after the first convoy of wounded French soldiers had arrived,
French President Raymond Poincaré officially inaugurated the hospital. Upon meeting him, Poincaré opined that Mignault "looked Norman". Several French figures attended the ceremony, namely the Canadian Minister of Overseas Military Forces,
Sir George Perley, prominent historian and member of the
Académie Française,
Gabriel Hanotaux, chief of French medical service,
Justin Godart, and
High Commissioner of Canada in Paris,
Philippe Roy. The hospital's capacity was initially set at 250 beds, but increasing cases of
syphilis and
gonorrhea among French soldiers led to expand its capacity to a full 600. To meet the increased activity, No. 4 Canadian Stationary Hospital was re-organized and re-designated as No. 8 Canadian General Hospital of the
Canadian Army Medical Corps. Simultaneously, Mignault was promoted
colonel. However, of bold nature, Mignault did run into some trouble. In 1916, Canadian authorities had to unravel and discharge several goods and services he purchased without authorization of relevant French firms. Embarrassed, Canadian authorities considered convening Mignault to
court-martial, but failed to follow through. He was however called back to Canada in November of that year.
End of war Upon his return home, Mignault was appointed in charge of military recruitment of French-speaking Canada. In spite of his humiliating dismissal from the field, he quite soon received several honours and distinctions. As Major General Sir
Eugène Fiset congratulated him for his services in the name of the
Canadian Ministry of Militia and Defence, France beset him the title of Knight of the
Legion of Honour. Mignault was transferred to Canada's
military reserve following the enactment of the
conscription of 1917. Designated a federal recruiting agent at the beginning of that year, he pursued his mobilising activities among French Canadians. Nevertheless, his military career came to a definite end on 15 September 1918, as he had entangled himself in another predicament with Canadian military authorities. ==Later life==