Battle cry
History: 

Antiquity: The war cry is an aspect of epic battle in Homer: in the Iliad, Diomedes is conventionally called "Diomedes of the loud war cry." Hellenes and Akkadians alike uttered the onomatopoeic cry "alala" in battle.
The troops of ancient Athens, during the Medic Wars and the Peloponnesian War were noted for going into battle shouting "Alala!" or "Alale!", which was supposed to emulate the cry of the owl, the bird of their patron goddess Athena.
The Western Huns attacked with terrifying battle cries.
One of the common Hindu war cries was "Hara Hara Mahadeva" meaning, "Hail to Mahadeva!" (Shiva).
A common war cry used in ancient Tamilakam was "Vetrivel, Veeravel", meaning, "Victorious vel, courageous vel." Vel is the spear of Murugan, the regional form of Kartikeya, the Hindu war deity. In the contemporary period, the battle cry "Vetrivel, Veeravel" is being used in the 191 Field Regiment of the Indian Army based in Madukkarai, Coimbatore.

Middle Ages: During the Scottish wars of independence, Scottish soldiers used Alba gu bràth as a battle-cry, a phrase that means 'Scotland for ever' (literally, 'Scotland until judgement'.) This was depicted in the film Braveheart during which Mel Gibson, playing William Wallace, shouts the phrase to rally his soldiers just before a battle commenced.
Each Turkic tribe and tribal union had its distinct tamga (seal), totemic ongon bird, and distinct uran (battle cry) (hence the Slavic urah "battle cry"). While tamgas and ongons could be distinct down to individuals, the hue of horses and uran battle cries belonged to each tribe, were passed down from generation to generation, and some modern battle cries were recorded in antiquity. On split of the tribe, their unique distinction passed to a new political entity, endowing different modern states with the same uran battle cries of the split tribes, for example Kipchak battle cry among Kazakhs, Kirgizes, Turkmens, and Uzbeks. Some larger tribes' uran battle cries:
Kipchak – "ay-bas" ("lunar head").
Kangly (Kangars) – "bai-terek" ("sacred tree").
Oguzes – "teke" ("mount")
Desperta ferro! ("Awake iron!" in Catalan) was the most characteristic cry of the Almogavar warriors during the Crown of Aragon military campaigns across the Mediterranean from the 12th through to the 14th centuries.
Deus vult! ("God wills it!" in Latin) was the battle cry of the Crusaders.
Montjoie Saint Denis!: battle cry of the Kings of France since the 12th century.
Santiago y cierra, España! was a war cry of Spanish troops during the Reconquista, and of the Spanish Empire.
On 14 August 1431, the whole Army of the Holy Roman Empire (of the 4th anti-Hussite crusade) was defeated by the Hussites in the Battle of Domažlice. Attacking imperial units started to retreat after hearing Ktož jsú boží bojovníci ("Ye Who Are Warriors of God") choral and were annihilated shortly after.
Allāhu Akbar (الله أكبر, "God is [the] Greatest") and Allāhu Allāh (الله الله, "God! God!") were used by Muslim armies throughout history. Al-naṣr aw al-shahāda (النصر أو الشهادة, "Victory or martyrdom") was also a common battle cry; the At-Tawbah 9:52 says that God has promised to the righteous Muslim warrior one of these two glorious ideals.
Óðinn á yðr alla (Odin owns you all) – A reference to Odin's self sacrifice at Yggdrasil. Attributed to Eric the Victorious.

Pre-modern: When suppressing peasants' rebellions in Germany and Scandinavia around 1500, such as in the Battle of Hemmingstedt, the Dutch mercenaries of the Black Guard yelled Wahr di buer, die garde kumt ("Beware, peasants, the guards are coming").  When the peasants counterattacked, they responded with Wahr di, Garr, de Buer de kumt ("Beware, Guard, of the peasant, [who is] coming").
The Spanish cried Santiago ("Saint James") both when reconquering Spain from the Moors and during conquest in early colonial America.
Polish "Winged Hussars" used to shout Jezus Maria ("Jesus, Mary") or Matka Boska ("Mother of God") during their charges.
King Henry IV of France (1553–1610), a pleasure-loving and cynical military leader, was famed for wearing a striking white plume in his helmet and for his war cry:  Ralliez-vous à mon panache blanc! ("Follow my white plume!").
Burmese soldiers of the Konbaung Dynasty under Alaungpaya were recorded to shout Shwebo-Thar (Sons of Shwebo) during the Konbaung-Hanthawady War.
Most of the Jaikaras were popularized by Guru Gobind Singh. The Sikhs have a number of battle cries or jaikara: the most popular ones are as follows:
Bolnaji (Respectfully Utter) – Waheguru (Wondrous Enlightener)
Deg Teg Fateh (Victory to Charity and Arms) – Birdh ki Paij Panth ki jit (Rout of the Enemy Victory of the Sikh Path)
Bole So Nihal...Sat Sri Akaal ("Shout Aloud in Ecstasy... True is the Great Timeless One"),
Nanak naam charhdi kalaa (May Thy name be exalted O Nanak) – Tere bhaanae sarbatt daa bhalaa (and all people prosper by Thy grace)
Waheguru ji ka Khalsa (the Community of the Pure belongs to the Wondrous Enlightener) – Waheguru ji ki Fateh (Victory belongs to the Wondrous Enlightener)
Raj Karega Khalsa – (The Khalsa will rule)  Aaakki Rahe Na Koye (And no opponent will remain)
Gaj ke jaikara gajaave fateh paave nihaal ho jaavae, Sat Sri Akaal gurbaar akaal hee akaal|| (excerpt from ardas of Buddha Dal prayerbook (gutka) praising the blessing of uttering jaikara proclaiming supreme truth).
The Pashtun soldiers' war cry against the Mughals was Hu, Hu.
The Gurkha (Gorkha) soldiers' battle cry was, and still is, "Jai Mahakali, Ayo Gorkhali!" ("Victory to Goddess Mahakali, the Gurkhas are coming!")
The "rebel yell" was a battle cry used by Confederate soldiers during the American Civil War.
Finnish light cavalry troops in the Swedish Army in the 17th and 18th centuries would use the battle cry "Hakkaa päälle!" ("Cut them down!" in Finnish), lending them the name Hackapell.
Irish regiments of various armies used and continue to use Gaelic War cries, "Faugh a Ballagh" ("Clear the way!") or "Erin go Bragh" ("Ireland Forever")
The Swedish army in the 18th and 19th centuries would be issued with the command to attack with "För Fäderneslandet, gå på, Hurra!" ("For the Fatherland, onwards, Hurrah!")
Argentine general José de San Martín is known in South America for his war cry: "Seamos libres, que lo demás no importa nada!" ("Let's be free, nothing else matters!").
In the Texas Revolution, following the Battle of Goliad and the Battle of the Alamo, Texan soldiers would use the battle cry "Remember Goliad! Remember the Alamo!"
In the Battle of Dybbøl in 1864, both Danish and German forces used "Hurrah" as a war cry.
During World War I in the Italian Front of 1915. Before battle, Italian soldiers would yell "Savoia" or "Avanti Savoia", which is "Come on Savoy!" or "Onwards Savoy!" in Italian (compare "For the king!" among British soldiers of the same era).

Modern: During World War II, Tennōheika Banzai (天皇陛下万歳, May the Emperor live for ten thousand years) served as a battle cry of sorts for Japanese soldiers, particularly in a "banzai charge". The most popular battle cry is "Ei ei oh" (エイエイオー), which is usually used at the start of battle.
"Avanti Savoia!" (English: Go Savoy!) was the patriotic battle cry of the Italian Royal Army during World War I and to a lesser extent, World War II.