There are many opinions among different investigators, as to the origin of the word "Karbala". Some have pointed out that "Karbala" has a connection to the "Karbalato" language, while others attempt to derive the meaning of word "Karbala" by analyzing its spelling and language. They conclude that it originates from the Arabic word "Kar Babel" which was a group of ancient Babylonian villages that included Nainawa, Al-Ghadiriyya, Karbella (Karb Illu. as in Arba Illu ), Al-Nawaweess, and Al-Heer. This last name is today known as Al-Hair and is where Imam Imam Hussain ibn Ali's grave is located.

The investigator Yaqut al-Hamawy had pointed out that the meaning of "Karbala" could have several explanations, one of which is that the place where Imam Hussain ibn Ali was martyred is made of soft earth—"Al-Karbalat".

According to Shi'ite belief, the archangel Gabriel narrated the true meaning of the name Karbal?’ to Muhammad: a combination of karb (Arabic: ??????, the land which will cause many agonies) and bal?’ (Arabic: ???????, afflictions)."

Climate

Karbala experiences a Semi-arid climate with extremely hot, dry summers and cool winters. Almost all of the yearly precipitation is received between November and April, though no month is truly wet.

Battle of Karbala

Karbala's prominence in Shia traditions is the result of the Battle of Karbala, fought on the site of the modern city on October 10, 680 AD (10 Muharram 61 AH). Both Imam Hussein ibn Ali and his brother Abbas ibn Ali were buried by the local Ban? Asad tribe, at what later became known as the Mashhad Al-Hussein. The battle itself occurred as a result of Husain's refusal of Yazid I's demand for allegiance to his caliphate. The Kufan governor, Ubaydallah ibn Ziyad, sent thirty thousand horsemen against Imam Hussein as he traveled to Kufa. The horsemen, under 'Umar ibn Sa'd, were ordered to deny Imam Hussein and his followers water in order to force Imam Hussein to agree to give an oath of allegiance. On the 9th of Muharram, Imam Hussein refused, and asked to be given the night to pray. On 10 Muharram, Imam Hussein ibn Ali prayed the morning prayer and led his troops into battle along with his brother Abbas. Many of Hussein's followers, including all of his present sons Ali Akbar, Ali Asghar (six months old) and his nephews Qassim, Aun and Muhammad were killed.

In 63 AH (682 AD), Yazid ibn Mu'awiya released the surviving members of Imam Hussein's family from prison. On their way to the Mecca, they stopped at the site of the battle. There is record of Sulayman ibn Surad going on pilgrimage to the site as early as 65 AH (685 CE). The city began as a tomb and shrine to Hussein and grew as a city in order to meet the needs of pilgrims. The city and tombs were greatly expanded by successive Muslim rulers, but suffered repeated destruction from attacking armies. The original shrine was destroyed by the Abbasid Caliph Al-Mutawakkil in 850 but was rebuilt in its present form around 979, only to be partly destroyed by fire in 1086 and rebuilt yet again.

Early modern

Like Najaf, the city suffered from severe water shortages that were only resolved in the early 18th century by building a dam at the head of the Husseiniyya Canal. In 1737, the city replaced Isfahan in Iran as the main centre of Shia scholarship. In the mid-eighteenth century it was dominated by the dean of scholarship, Yusuf Al Bahrani, a key proponent of the Akhbari tradition of Shia thought, until his death in 1772, after which the more state-centric Usuli school became more influential.

The Wahhabi Muslim sack of Karbala occurred in 21 April 1802 (1216 Hijri) (1801), under the rule of Abdul-Aziz bin Muhammad the second ruler of the First Saudi State, when 12,000 Wahhabi Muslims from Najd attacked the city of Karbala. The attack was coincident with the anniversary of Ghadir Khum event, or 10 Muharram. This fight left 3,000–5,000 deaths and the dome of the tomb of Husayn ibn Ali, grandson of Muhammad and son of Ali bin Abi Talib, was destroyed. The fight lasted for 8 hours.

After the First Saudi State invasion, the city enjoyed semi-autonomy during Ottoman rule, governed by a group of gangs and mafia variously allied with members of the 'ulama. In order to reassert their authority, the Ottoman army laid siege to the city. On January 13, 1843 Ottoman troops entered the city. Many of the city leaders fled leaving defense of the city largely to tradespeople. About 3,000 Arabs were killed in the city, and another 2,000 outside the walls (this represented about 15% of the city's normal population). The Turks lost 400 men. This prompted many students and scholars to move to Najaf, which became the main Shia religious centre. Between 1850 and 1903, Karbala enjoyed a generous influx of money through the Awadh Bequest. The Shia ruled Indian Province of Awadh, known by the British as Oudh, had always sent money and pilgrims to the holy city. The Oudh money, 10 million rupees, originated in 1825 from the Awadh Nawab Ghazi-ud-Din Haider. One third was to go to his wives, and the other two thirds went to holy cities of Karbala and Najaf. When his wives died in 1850, the money piled up with interest in the hands of the British East India Company. The EIC sent the