Early modern warfare
However, the power formerly wielded by a heavy cavalry-focused army was at an end. For the first time in millennia, the settled people of the agricultural regions could defeat the horse peoples of the steppe in open combat. The power of the Mongols was broken in Russia and, no longer threatened from the east, Russia began to assert itself as a major force in European affairs. Never again would nomads from the east threaten to overrun Europe or the Middle East. In the Siege of Kazan (1552), Russia had employed artillery, sappers, cavalry and infantry armed with arquebus (Streltsy), while the Khanate of Kazan had only employed cavalry. The use of sappers proved decisive.
The one exception to this was the Ottoman Empire, which had been founded by Turkish horsemen. The Ottomans were some of the first to embrace gunpowder artillery and firearms and integrated them into their already formidable fighting abilities. As European infantry became better armed and disciplined, by about 1700, the Ottoman forces began to be regularly defeated by the troops of the Austria and Russia.

Naval warfare: The Age of Sail (usually dated as 1571–1862) was a period roughly corresponding to the early modern period in which international trade and naval warfare were dominated by sailing ships and gunpowder warfare, lasting from the mid-16th to the mid-19th centuries. The spread of European power around the world was closely tied to naval developments in this period. The caravel for the first time made unruly seas like the Atlantic Ocean open to exploration, trade, and military conquest. While in all previous eras, European navies had been largely confined to operations in coastal waters, and were generally used only in a support role for land-based forces, this changed with the introduction of the new vessels like the caravel, carrack, and galleon, and the increasing importance of international waterborne trade in the sixteenth and seventeenth centuries. The new caravels were large enough and powerful enough to be armed with cannons with which they could bombard both shoreline defenses and other vessels.

Africa: 

Somalia: The Ethiopian–Adal War was a military conflict between the Ethiopian Empire and the Adal Sultanate from 1529 until 1543. The Imam Ahmad ibn Ibrihim al-Ghazi (nicknamed Gurey in Somali and Gragn in Amharic (ግራኝ Graññ), both meaning "the left-handed") came close to extinguishing the ancient realm of Ethiopia, and converting all of its subjects to Islam; the intervention of the European Cristóvão da Gama, son of the famous navigator Vasco da Gama, helped to prevent this outcome. Many historians trace the origins of hostility between Somalia and Ethiopia to this war. Some historians also argue that this conflict proved, through their use on both sides, the value of firearms such as the matchlock musket, cannons, and the arquebus over traditional weapons. Imam Ahmed was the first African commander to use cannon warfare on the continent during the Adal's conquest of the Ethiopian Empire under Dawit II.

Asia: 

China: Gunpowder was invented in China in the Tang dynasty. It started being broadly used in warfare in the Song dynasty. From the 7th through 10th century, there were widespread advances in gunpowder technology. While the Europeans were pressed on technological advancements and military developments with gunpowder, the Chinese fell back in regards to further developing military technology. This was due to the fact that the Chinese were not as heavily engaged in wars or conquests as the Europeans. Notably, when the Chinese were at war with the Portuguese, for example, they swiftly adapted to military technology, and adopted Western style guns.
The Chinese pioneered the use of gunpowder weapons, crossbows, advanced forms of arms and armor, naval and nomadic cavalry. Thus, the Chinese even adopted Western military technology. Interestingly, the Chinese had many descriptions of how they utilized their technology. For Ming China, they had experiences on the battlefield: against Chinese rebels, Shan elephants, and Mongol horsemen. Nonetheless, under the Ming dynasty, intensively practiced tactical strategies based on their firearm use. Qi Jiguang and his troops used innovative battle techniques such as counter marching, dividing the troops, as a flexible way of adapting to the battlefield. These tactics were proved effective during the Sino-Dutch War beginning in 1661. While the Chinese were undermined as the inferior empire due to lack of weaponry, their strict adherence discipline and tactical strategy led to them defeating the Dutch. This draws a parallel to the Sino-Portuguese conflict. During the first war, in 1521, the Portuguese firepower was far more effective than the Chinese. As they witnessed the power of Portuguese artillery, the Chinese better prepared for the war in 1522. They modified, adapted, innovated and improved. The Chinese were a display of rapid militarization, as they instilled Western style learnings to their knowledge of artillery and war tactical strategy.
The fire arrows (rocket arrows) were first reported to have been used by the Southern Wu in 904 during the siege of Yuzhang.

Safavid Empire: Soon after the Ottoman Empire, two other Muslim gunpowder empires appeared: the Safavid Empire in Iran and the Mughal Empire in India. They both began in the early 16th century but later collapsed in the 18th century.
The refusal of their Qizilbash forces to use firearms contributed to the Safavid rout at Chaldiran in 1514.
After this, the Persians actively sought to acquire the skills to make and use firearms. In a report given to the Council of Ten on 24 September 1572, the Venetian envoy Vincenzo di Alessandri noted how firearms had become integrated into the Persian army:

They used for arms, swords, lances, arquebuses, which all the soldiers carry and use; their arms are also superior and better tempered than those of any other nation. The barrels of the arquebuses are generally six spans long, and carry a ball little less than three ounces in weight. They use them with such facility that it does not hinder them drawing their bows nor handling their swords, keeping the latter hung at their saddle bows till occasion requires them. The arquebus is then put away behind the back so that one weapon does not impede the use of the other.

Japan: The Japanese were introduced to early firearms by Portuguese traders arriving with European style arquebuses onto the island of Tanegashima, near the island of Kyushu in September 1543. The impact of this event would revolutionize Japanese strategy throughout the Sengoku-jidai, revolving around tactics that centered on usage of firearms.
While memoirs by Fernão Mendes Pinto attribute himself and Diogo Zeimoto as the traders to initially introduce firearms to Japan, studies of said memoirs call this claim highly embellished, and therefore the validity of this claim falls into question. Daimyō of the period, searching for any sort of new tactical edge over their regional rivals, were quick to acquire and have blacksmiths under their retinue, reverse-engineer and reproduce the early European firearms. Portuguese traders visiting Japan several years later found that the Japanese had successfully reproduced hundreds of arquebuses, and by 1546, a rough estimate of over 300,000 of the early firearms were in circulation throughout Japan. Early production of said firearms were limited to the general region of Kyushu, though gunsmiths would eventually migrate throughout Japan. Different schools started to emerge from this migration. with notable examples from Sakai, Yokkaichi, and Kunitomo being the most prevalent. Moreover, production of small arms ranged from the early Tanegashima arquebus, to later production teppo, which also subdivided into arquebuses of varying caliber and length, to "hand cannons" favored by those of the Shimazu clan.
Japanese military strategy upon receiving the new weapon, began to gradually shift towards infantry based tactics, rather than those that favored horseback cavalry. This is most famously portrayed at the Battle of Nagashino in 1575, where Oda Nobunaga's 3,000 riflemen had handily dispatched the much larger Takeda clan cavalry force using the first recorded utilization of volley fire. However, certain studies have disputed the claim that Nobunaga was the first to utilize this tactic, though Japanese forces were utilizing it far earlier than other world contemporaries. Japanese battle planning soon centered around manipulating one's enemies into allied fortified positions to rapidly dispatch enemy manpower, only engaging in hand-to-hand combat when necessary.
Similarly, Japanese daimyō were introduced to artillery in 1551, when a trader claiming to be the king of Rome presented elements of the Ōtomo clan with two examples of field artillery. As with their small arms counterparts, many warlords wished to quickly adopt the weapon in order to gain an advantage over their contemporaries, but difficulties in producing suitable reproductions led to limited early usage in comparison. As with personal firearms, Oda Nobunaga was early to adopt the new weapon, and later, after his death, one of his retainers Toyotomi Hideyoshi would use cannons to destructive effect to lay siege to Kanki Castle in 1582.