Problem: Om Shanti Om (Hindi pronunciation: [o:m Sa:ntI o:m]) is a 2007 Indian romantic melodrama film directed and co-written by Farah Khan with Mayur Puri and Mushtaq Shiekh. It stars Shah Rukh Khan as Om, a junior artist of the 1970s who has a crush on a secretly married superstar, played by Deepika Padukone. Her husband, a producer played by Arjun Rampal, kills her in a fire;

Om Shanti Om was made on a budget of Rs400 million. The first scene to be filmed was one where Talpade's character tells Shah Rukh's character that he will be a hero; Shah Rukh was an hour late for filming. Farah was pregnant with triplets while filming and experienced difficulties while shooting, she would constantly vomit while directing the film. The film was shot entirely in sync sound; Farah dismissed rumours of Padukone's voice being dubbed. In 2015, however, Mona Ghosh Shetty admitted to have dubbed for Padukone in the film. Afake fight scene involving a stuffed tiger was inspired by a similar scene in the film Tarzan 303. Old cars owned by actors Rajesh Khanna and Hema Malini were used for filming for authenticity.  A number of references to real life was also filmed, including a scene in which Om saves Shantipriya from a fire, which was a spoof of Sunil Dutt rescuing Nargis from a fire on the sets of Mother India (1957). For a shot involving a Filmfare Awards ceremony, Khan stood on the red carpet of an actual Filmfare Award ceremony and requested actors to dictate dialogues as she stated. The song "Deewangi Deewangi" was shot over a period of six days. The song "Dhoom Tana" has digitally altered guest appearances, which included Sunil Dutt from Amrapali (1966), Rajesh Khanna from Sachaa Jhutha (1970) and Jeetendra from Jay Vejay (1977). Farah wanted to film Shakira for filming a special appearance had made her commit a few days for the role. Due to the uncertainty of her dates, the idea was scrapped.  In February 2007, a filming schedule was completed in Film City. It was then reported that filming would move outdoors after Shah Rukh completed filming for Kaun Bannega Crorepati. In October 2007, Abhishek Bachchan finished filming for his cameo appearance; he shot between 10 and 2 in the night for his screen time of about one and a half minutes. Filming of the last sequence and the end-credit song was done in Film City. Farah continued the tradition of featuring an end-credits song beginning with Main Hoon Na (2004).  Om Shanti Om was produced by Shah Rukh's wife Gauri Khan under their Red Chillies Entertainment banner. While Marching Ants handled the publicity design, Gauri was the presenter. Shyam Kaushal, Amar Shetty and Shah Rukh were the action directors. The film's final reel length was 4013.94 ft (1223.45 m).

what was principal photography?

Answer with quotes: a filming schedule was completed in Film City.


Problem: Isabella I (Spanish: Isabel, 22 April 1451 - 26 November 1504) reigned as Queen of Castile from 1474 until her death. Her marriage to Ferdinand II of Aragon became the basis for the political unification of Spain under their grandson, Charles I. After a struggle to claim her right to the throne, she reorganized the governmental system, brought the crime rate to the lowest it had been in years, and unburdened the kingdom of the enormous debt her brother had left behind.

At the end of the Reconquista, only Granada was left for Isabella and Ferdinand to conquer. The Emirate of Granada had been held by the Muslim Nasrid dynasty since the mid-13th century. Protected by natural barriers and fortified towns, it had withstood the long process of the reconquista. On 1 February 1482, the king and queen reached Medina del Campo and this is generally considered the beginning of the war for Granada. While Isabella's and Ferdinand's involvement in the war was apparent from the start, Granada's leadership was divided and never able to present a united front. It still took ten years to conquer Granada, however, culminating in 1492.  The Spanish monarchs recruited soldiers from many European countries and improved their artillery with the latest and best cannons. Systematically, they proceeded to take the kingdom piece by piece. In 1485 they laid siege to Ronda, which surrendered after only a fortnight due to extensive bombardment. The following year, Loja was taken, and again Muhammad XII was captured and released. One year later, with the fall of Malaga, the western part of the Muslim Nasrid kingdom had fallen into Spanish hands. The eastern province succumbed after the fall of Baza in 1489. The siege of Granada began in the spring of 1491 and at the end of the year, Muhammad XII surrendered. On 2 January 1492 Isabella and Ferdinand entered Granada to receive the keys of the city, and the principal mosque was reconsecrated as a church. The Treaty of Granada was signed later that year, and in it Ferdinand and Isabella gave their word to allow the Muslims and Jews of Granada to live in peace. An uprising by the Moors in 1500 caused the Catholic side to consider that the Moors had violated the Treaty: this gave them a justification for revoking its provisions. See Morisco Revolt.  During the war, Isabella noted the abilities and energy of Gonzalo Fernandez de Cordoba and made him one of the two commissioners for the negotiations. Under her patronage, De Cordoba went on to an extraordinary military career that revolutionised the organisation and tactics of the emerging Spanish military, changing the nature of warfare and altering the European balance of power.

How did he revolutionize it?

Answer with quotes:
changing the nature of warfare and altering the European balance of power.