Army

An army was a military land force.

Daleks
The first known Dalek army was assembled fifty cycles after the Thal-Dalek battle. Having survived the battle, the Dalek Supreme manufactured hundreds of Dalek War Machine casings and led its revived army against the Thal City. When the First Doctor took control of the ionising towers, the Dalek army retreated and was destroyed when Ian Chesterton overloaded the power feeds of the Dalek City. (AUDIO: Return to Skaro)

During the reign of the Dalek Empire, the Daleks began keeping armies in suspended animation, most notably the army on Spiridon. (TV: Planet of the Daleks, WC: The Sentinel of the Fifth Galaxy) In the Last Great Time War, the Daleks began boosting their overworked army, converting conquered humans into Daleks at an accelerated rate to serve as cannon fodder and harvesting versions of themselves from alternate realities to serve as shock troopers, creating the Skaro Degradations. (PROSE: Engines of War) Numbering at a "billion billion" units, the Dalek army attacked Gallifrey on the last day of the war, destroying itself in its own crossfire when the planet disappeared. (TV: The Day of the Doctor) The post-Time War New Dalek Empire was said to have a standing large enough to "slaughter the cosmos". (TV: Journey's End)

When the New Dalek Paradigm was raised, they used the production facilities of Goth to quickly build a galaxy-conquering army. Red Drones initially made up the bulk of the Dalek Imperial Army before the New Paradigm's repeated failures led the Prime Minister of the Daleks to replace them with the bronze Daleks associated with the Time War so as to provoke the most fear across the universe. The larger Red Drones became an officer class, albeit one kept safely away from the front line. Historians who studied the Dalek race believed, but could not confirm, that the New Paradigm had deployed the totality of its army during the Siege of Trenzalore to prevent the return of the Time Lords and as a consequence, its destruction at the hands of Eleventh Doctor had been the final defeat of the Daleks. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Others
The Fourth Doctor marched with the Filipino Army in the 51st century on Reykjavik during World War VI. (TV: The Talons of Weng-Chiang)

Morris Heggie was a general in the Union Army during the American Civil War. (PROSE: Blood and Hope)

Sinnott was the General of the Irish Army and ordered them to attack when negotiations with Oliver Cromwell failed. Ace wanted to stop him from fighting. (AUDIO: The Settling)

The Eleventh Doctor assembled an army (mostly composed of Silurians and Judoon) to rescue Amy Pond from Demons Run. (TV: A Good Man Goes to War)

The War Lords attempted to create an army capable of universal conquest by brainwashing humans from various Earth conflicts and recruiting those who survived the War Games. (TV: The War Games) When this failed, the War Lords tried again with a more streamlined approach centred on Nazi Germany. (PROSE: Timewyrm: Exodus)

When the First Doctor was a child, he feared that he would not become a Time Lord and would instead be forced to join the Gallifreyan army. (TV: Listen) During the Last Great Time War, the Time Lord army was overseen by the War Council, which was itself led by the General. (TV: The Day of the Doctor)

Upon discovering that Mark Seven was the First Movellan, the Tenth Doctor suspected that whomever had recovered Mark had done so with the intent to use him as the template for an anti-Dalek robotic army. (AUDIO: The Triumph of Davros)

In an emergency transmission sent out by the TARDIS, the Thirteenth Doctor claimed to be self-isolating, or hiding, from an army of Sontarans. (WC: Message from the Doctor)