The capture of Aguinaldo and the surrender of Trias in March 1901 left the 1st republican army without a leader. Malvar's ascendancy and taking over of the mantle of leadership signaled the continuation of the resistance and provided a much-needed boost to the morale of Filipino troops still fighting in the field. His proclamation was clearly directed at the masses, whose commitment he pursued to counteract the wavering backing of a portion of the wealthy elites. Malvar adopted a new approach to expand his base of support and to revitalize the resistance. With the April 12 proclamation and related efforts, the southern Tagalog resistance was galvanized until December 1901, when Gen. Franklin Bell took over and implemented extreme measures to capture Malvar.

Excerpts from Glenn Anthony May discusses it in his book Battle for Batangas, A Philippine province at war..

Malvar Takes Charge, Mid-April 1901

Almost a month had passed since Trias had surrendered, and in the interim, there was no little confusion in the ranks of the Filipino leadership about how to proceed in the war against the Americans. Reports had circulated among the guerillas in the southern Tagalog region that various generals were on the point of leaving the field and that mass surrenders had taken place in other parts of the Philippines, so many unconfirmed stories were making the rounds, in fact, that most commanders were unsure about exactly who was directing the war effort. So on April 12, Malvar, aware that the resistance was in desperate trouble, issued a proclamation designed to provide direction to his "Brother and companions in the struggle."

The Batangueño general began by announcing that, in accordance with a decree issued by Aguinaldo in June 1900 establishing an order of succession and until a general assembly of military leaders could be held to discuss the issue further, he, Malvar, had assumed the position formerly held by Mariano Trias: second in command of the revolutionary army and commander of the provinces of the Southern Department. He took this step, he claimed, with great reservations.

Realizing my unworthiness, I feel like I lack the strength to perform this difficult job. I would gladly turn it over to another, if not for my hope that all of you will give me assistance, because without it, I can accomplish nothing more than the lowest-ranking soldier (can accomplish).

Likening himself to a humble beggar who, "in spite of illness, continues walking on to the end," he vowed to persevere in the war against the Americans.

Malvar then turned to other subjects. As we have seen, one striking feature of Aguinaldo's government had been its consistent promotion of the interests of the upper rungs at the expense of the lower, and one result of such policies had been the government's apparent failure to attract widespread support among lower-class Filipinos. Malvar signaled his intention to change that state of affairs:

Let us do away with the untrue stories that the uneducated will be weeded out afterwards, because any brother in the field who has learned to ignore dangers in his life in defending the fatherland; whose good conduct has been shown in protecting the chastity of women and the lives, honor, and property of noncombatants, native or foreign; who has organized and trained a unit or company; and who cannot be disparaged by his compatriots, such a man is a well-spring of knowledge.

Yes, be reassured, and answer the call of the fatherland and be prepared for a just reward.

Henceforth, the contributions of humble Filipinos to the war effort would be appreciated.

Malvar's proclamation. of April 12 is noteworthy on at least two counts. First, it marked the initial step in the Batangueño leader's elevation to the command of the entire Filipino Army. In the next few weeks, Malvar began to issue orders to officers in the Southern Department, and on July 13, 1901, after attempting without success to organize the general assembly he had referred to his April proclamation, he assumed the position of supreme commander of the “Liberating Forces” until a meeting could be arranged.

Second, April 12, 1901 marked a change of direction in the southern Tagalog resistance. Whereas Aguinaldo had concentrated on gaining the favor of Filipinos of means, Malvar, having recently lost the support of part of his elite following, was delivering a message intended to appeal to the occupants of the bottom rungs. And if the content of the proclamation was bound to resonate with a lower-class audience, the same was true of the form. As Reynaldo Ileto has shown, the language used by Malvar in his April proclamation was remarkably similar to that found in the manifestoes and writings of Andres Bonifacio and several other leaders of popular uprisings of earlier days. That is to say, he employed some of the same words and symbols that had proved to be so effective in mobilizing the peasantry during the initial stages of the struggle against Spain. Hence, Malvar's characterization of himself as a humble man and a beggar echoed words used by Apolinario dela Cruz, the key figure in a popular movement in the southern Tagalog region in the 1840s, and other passages in the proclamation were reminiscent of the writings and speeches of Bonifacio and Apolinario Mabini. "In fact," Rey Ileto writes,” it is Malvar speaking in light of the masses’ perceptions of the qualities that a meaningful, popular struggle should have.”

Beginning in April 1901, the southern Tagalog resistance was transformed.