18th Century (1701-1799) arms and tactics reshaped the battlefields to begat the "Age of Rifles". Gunpowder came onto the world stage in the form of ranged fire from muskets and artillery, giving rise to Dragoon units (horse-mounted infantry), the infantrymen and a famous world generals (including Napoleon Bonaparte of France).
The styles of warfare in the 18th Century changed by way of new organizational approaches to fielding and maintaining a professional army and the emergence of gunpowder for use in weaponry. The English Parliament was the first such governing body to act on this measure, creating the "New Model Army" as a professional band of soldiers under a strict organizational structure. This was a turn away from the old days of recruiting armies from the populace or hiring out non-aligned mercenaries to further political causes. At the time of the New Model Army, local militias represented the bulk of fighting forces, especially in England, but throughout Europe as well. Parliament, in a battle for power with King Charles I, sought to build up a professional force of fighting men (complete with uniforms) under a single organizational banner and efficiently trained leadership. In doing so, they created the world's first "professional" army.
The New Model Army featured and matchlock- and flintlock-actuated musket guns coupled to advancements made in gunpowder as a projectile propellant. It was the "gun" that effectively caused the end of the knight some time before as musket balls could easily pierce even the most staunch armor. In time, armor fell to disuse and brought simple cloth uniforms into play. Though armored pikemen were still of service along the front lines as a counter to cavalry, it was the infantryman - armed with gunpowder muskets - that began making a difference on the battlefield. These infantrymen, with superior training in tactics in tow, functioned in specialized formations that could best utilize the firepower available. A single volley could easily demoralize and disorganized a group of advancing soldiers and horsemen - particularly if the advancing force was of lesser training, discipline and organization.
Armies could also now utilize artillery as an effective ranged means to demolish their enemies. Infantry on horseback developed into equally effective killers as "Dragoons", armed with muskets and sabres, providing a fast-moving and powerful offensive battlefield piece. In all, the efficiency of an organized assault, defense or even retreat was now taking over the place of the rag-tag approach of simple running and bashing into one's enemy with piercing or blunt objects. It is notable that swords were still a part of the modern battlefield but solely utilized for extreme close combat (as were musket-butts). Soldiers would stand shoulder to shoulder in formation, allowing one line to shoot, kneel and reload while the second line fired over the heads of the first row. The soldiers, in response to the battlefield superior barking commands, could also form stout defensive boxes, ensuring that all of their flanks were covered from enemy penetration from any angle. This type of warfare would last well into the 20th Century while ultimately seeing final major action in the trenches of World War I (1914-1918).
The changes in warfare during the 18th Century fueled the cause of the super powers to spread their imperialistic tendencies through colonization against weaker nations. Nations in Asia, Africa and the Middle East were now subject to the organized, highly-trained and effective fighting forces fielded by the British, German, French, Belgian, Spanish and Portuguese empires. The New Model Army-type of organization ensured swift and crushing defeats on more disorganized tribal armies of the countries they ravaged. In all, this colonization led to the introduction of European customs and traditions around the world, help spread the European Church's message (and influence) and implement the tactic of intimidation over force to overtake struggling and underpowered nations. These changes to the world stage helped usher in new alliances, showcase new areas teeming with natural resources (including slave labor) and forge new strategic footholds of which some remain even today (2014). Rivalries between world powers also led to railway expansion throughout the continent of Africa as natural resources were pillaged for the benefit of the invading kingdoms.
In all, warfare became something of a less brutish effort on some levels for the individual soldier - though no less bloody and violent. The "intimacy" of sword combat was now forever gone, giving way to ranged skirmishes that could only be managed through rifle and cannon fire. No longer would a general have to sacrifice half of his army to an initial offensive thrust - but instead meticulously calculate the effective use of his troops through formations, battlefield advantages and overpowering artillery. The changes in modern warfare during the 18th Century changed the battlefield through the new idea of military organization and the advancement of gunpowder in firearms - forever changing the world.