August 19, 2010 is an important date in the history of Indian mathematics. It was the day on which the President of India inaugurated the International Congress of Mathematicians (ICM) in the city of Hyderabad. The ICMs have a hundred-year-old history: since the first Congress was held in Zurich in 1897, they have been held regularly every four years except for breaks during the two world wars. India was holding it for the first time (and it was only the third time that an Asian country was hosting this most prestigious of mathematical events).

The Indian bid to hold the Congress was initiated by the National Board for Higher Mathematics (NBHM), an agency set up by the Government of India for the promotion of mathematics in the country. A Provisional Organising Committee (POC) consisting of some 30 members, most of them mathematicians, drawn from all over the country was formed (by NBHM) before submitting the bid. A subcommittee of the POC prepared the bid and designed a logo for ICM 2010. The logo is a depiction of the standard fundamental domain for the modular group acting on the upper half plane with the famous Ramanujan conjecture written along the rim of the unit circle.

The Executive Committee of the International Mathematical Union (IMU) recommended the acceptance of India's bid to the General Assembly (GA) of the IMU held at Santiago de Compostela, Spain in August 2006 and the GA endorsed it. The Government of India's enthusiastic support expressed in a letter from the Indian Prime Minister to the President of the IMU welcoming the holding of the ICM in India and an informal pledge of financial support to the tune of 40 million Rupees by the Department of Atomic Energy (DAE) of the Government of India were perhaps crucial to our winning the bid.

Immediately after this, the Indian Organising Committee started on the organisational work in earnest. A compact subcommitee of the Organising Committee — the "Executive Organising Committee" (EOC) — was set up to ensure efficient functioning. The members of the Committee were: M S Raghunathan (Chair), S G Dani (Vice Chair), Rajat Tandon (Secretary), T Amarnath (Treasurer), R Balasubramanian, S Kesavan, S Kumaresan, Gadadhar Misra, P Mukherjee, R N Puri, G Rangarajan, Rahul Roy and Dinesh Singh.

Several subcommittees were formed and assigned specific responsibilities. The subcommittees always had some members of the EOC on them. The Editorial Committee for the Proceedings of the Congress was chaired by Rajendra Bhatia. An EOC member of each of the committees (other than the Editorial Committee) was given the charge of implementing the decisions taken by the Committee.

The first task taken up by the Organising Committee was to ensure that adequate funding will be available for the Congress. DAE made a firm commitment to provide sixty million Rupees for the Congress, thereby becoming the principal sponsor of the ICM. The IMU provided four million Rupees. The Department of Science Technology was approached to fund a project under which some twenty satellite meetings were to be supported and also some 1,000 Indian mathematicians and students could be fully supported for participation in the Congress. Approaches were also made to corporate organisations as well as individuals. Among the major contributors were Shri R Thyagarajan of Chennai who donated six million Rupees and Shri Narayanamurthy of Infosys who, apart from a cash grant of two million Rupees, made available the excellent guesthouse run by Infosys in Hyderabad free of cost. More than 500 of the delegates were accommodated in the guesthouse.

Next the EOC held discussions with the Vice Chancellor of the University of Hyderabad who kindly agreed to the proposal by the EOC that the University undertake the organisation of the ICM as a project to be implemented under the direction of the EOC. The principal sponsor DAE also accepted this arrangement and the funds for the organisation of the ICM were released to the University as and when required.

The Chair H W Lenstdra of the Programme Committee appointed by the IMU EC provided the EOC with the list of invited plenary and sectional speakers and also the panel participants in March 2009. Invitations were sent out by M S Raghunathan (Chair EOC) in April 2009. All invited sectional speakers were offered free registration and were requested to submit the absracts and texts of their talks by March 15, 2010. The plenary speakers and panelists were requested to submit abstracts by that date and manuscripts by July 15, 2010. About ten invitees declined and were replaced by other names by the Programme Committee. The IMU EC also wanted two additional lectures in the programme: the Abel Lecture sponsored by the Norwegian Academy to be given by S R S Varadhan, the 2006 Abel Laureate and the Noether Lecture to be given by Idun Reiten and these were included in the programme.

The European Women in Mathematics approached the EOC for support to organise a two-day meeting focusing on contributions of women to mathematics to be held just ahead of the ICM in Hyderabad.* The EOC responded favourably to the request and formed a local organising committee chaired by Shobha Madan of IIT Kanpur for the purpose. The EOC also extended financial support of two million Rupees for organising the meeting which was given the name International Congress of Women Mathematicians. It was to be held during August 16–18, 2010 at the University of Hyderabad.

It is a long tradition that the prestigious Fields Medals instituted by the IMU are given away at the inaugural function of the ICM by the Chief Guest. The prizes instituted later, the Nevanlinna Prize and the Gauss Prize are also given to the winners by the Chief Guest on this occasion. The IMU EC informed the EOC that a new prize called the Chern Prize was being instituted and was also to be given away for the first time at the inaugural function of the ICM in Hyderabad. The EOC approached the President of India, Shrimathi Prathibha Devisingh Patil with the request that she inaugurate the ICM on August 19, 2010 and give away the Prizes. The President accepted the EOC's invitation and the inaugural function was held at 11 am on August 27, 2010.

The President was received on her arrival at the venue by S Hasnain (Vice Chancellor, University of Hyderabad), Laszlo Lovasz and M S Raghunathan. Also seated on the dais were the Governor and the Chief Minister of Andhra Pradesh, Martin Grotschel (Secretary, IMU), Laszlo Lovasz, M S Raghunathan, S Hasnain, Louis Nirenberg (the recipient of the Chern Medal Award), and Rajat Tandon.

The proceedings began with the playing of the national anthem. Raghunathan welcomed the President, other dignitaries and the delegates to the Congress. Lovasz then addressed the gathering as the President of the IMU. This was followed by the President of India giving away the prizes after Grotschel announced the composition of each of the prize committees followed by the name of the prize winner and the citation. Altogether seven prizes were given away: four Fields Medals, Nevanlinna Prize, Gauss Prize and Chern Prize. The President then addressed the gathering. She spoke on India's long engagement with mathematics and its active role in international cooperation. She offered congratulations to the prize winners and welcomed the delegates wishing them a pleasant and fruitful stay in India. The Chief Minister also extended his welcome to the delegates. Rajat Tandon proposed the vote of thanks. The function ended with the playing of the national anthem again. The programme was conducted by Chandna Chakraborthy.

The inaugural function continued after the President left when Lovasz and Martin briefed the delegates about the various initiatives connected with the ICNS taken by the EC since the previous congress in Spain in 2006. The passing away of V Arnold and H Cartan who were both involved with IMU activities in the past was observed with condolences. Raghunathan was named President of ICM 2010 by Lovasz. The meeting ended with a brief reply by Raghunathan.

In the afternoon, there were laudations of the Fields Medallists: H Furstenberg was the Laudator for E Lindenstrauss, J Arthur for Ngo Bao Chau, H Kesten for S Smirnov and H T Yau for C Villani.

This was followed by the laudation for the Nevanlinna Prize winner D Spielman by G Kalai. The academic programme for the day ended with the Abel Lecture by Varadhan. K R Parthasarathy was in the chair. In the evening the EOC hosted a dinner in honour of the invited speakers. The three hundred odd invitees were people involved in the organisation of the ICM.

On the second day, there were special sessions (9 am to 12:30 pm) devoted to the Gauss and Chern Prizes. There was a talk on the work of Yves Meyer, the Gauss Prize winner by Ingrid Daubechies. The session on the Chern Prize was more elaborate. There was a talk about Chern's work and a video film on him was also shown. May Chu, Chern's daughter spoke about her father. Yan Yan Li spoke on the work of Louis Nirenberg, the (first) Chern Prize winner.

In the evening, there was an Indian Classical Dance Programme by Nrityashree, a dance troupe led by a renowned Baharat Natyam dancer Professor C V Chandrasekhar. The dance-drama titled "Panchamahabhuthangal" was a depiction through dance of the functioning of the five "bhutas" — Bhumi (earth), Jalam (water), Akasha (sky), Vayu (air) and Agni (fire). Later in the evening, the EOC also hosted a dinner at Shilpa Kala Vedika for all the delegates and accompanying persons.

From the third day onwards, there were four plenary lectures each day from 9 am to 2:45 pm with a break for lunch. The 1:45 pm to 2:45 pm slot was exclusively reserved for lectures by the Fields Medallists and the Nevanlinna Prize winner. As many as 8 parallel sessions were held for the sectional talks and the contributed papers/posters. The 45-minute sectional talks were held from 3 pm to 6:30 pm. The plenary and sectional talks were chaired by distinguished mathematicians, most of them were from India.

The EOC organised a chess event on August 24. Viswanathan Anand, the world chess champion played simultaneous chess against 40 delegates. (A month before the event on-line application was open for delegates desirous of playing against Anand. Forty delegates were chosen on a first-come first served basis. There was a fee of 4,000 Rupees.) Except for a solitary draw by a 14-year-old, Anand won all the other games. Each player received a box of chessmen and the board on which he or she played autographed by Anand. Other spectators could also collect Anand's autographs after the event.

Another cultural event organised by the EOC was a performance of the play "A Disappearing Number" by the well known theatre company Complicite of London. The play was performed on two consecutive days August 21 and 22. It was open to the general public of Hyderabad, but the delegates could book their tickets on-line a week ahead of the public. It was performed at the Global Peace Auditorium and both shows were sold out.

On August 25, there was a Classical Hindusthani music concert by Ustad Rasheed Khan, one of India's great exponents. EOC had also organised two lectures on music appreciation by Sunil Mukhi on August 22 and 24 for the benefit of the delegates who may be unfamiliar with Indian music.

In June 2010 the EOC instituted a one-time international prize called the "Leelavati Prize" (with a value of one million Rupees) for public outreach work for mathematics. Nominations for the prize were sought from mathematical societies around the world and also from mathematics departments of many universities and research institutions. The Prize Committee chaired by M S Narasimhan awarded the prize to Simon Singh, citing among other things the book as well as the documentary film he had produced on Fermat's Last Theorem. Singh gave a public lecture on August 25 on the making of the documentary.

There were several panel discussions all of which were held during the late afternoons.

In the morning of the August 27, Idun Reiten gave the Noether Lecture, chaired by Claire Voisin. The closing ceremony was held in the afternoon. At this ceremony, on behalf of the International Commission on History of Mathematics, Kim Plofker handed the 2009 Kenneth O'May Prize for History of Mathematics to R C Gupta, the first Indian to be awarded this prestigious prize.

Lovasz handed the Leelavati Prize to Simon Singh. Lovasz also announced that Ingrid Daubechies will take over from him as President of the IMU from January 2011. It was also announced that a permanent secretariat for the IMU was being set up in Berlin. It was also formally announced that Korea would host the 2014 Congress in Seoul. The Korean delegation was congratulated by those on the dais and the Korean delegate on the dais extended a warm welcome to all present to ICM 2014. The meeting ceremony ended with a vote of thanks by Rajat Tandon.

The Norwegian, German, French, Korean and Vietnamese embassies and the Canadian High Commission held receptions during the Congress: The US National Committee and the London Mathematical Society as well as the Indo-French Institute for Mathematics also hosted receptions, mainly in honour of the prize winners and invited speakers. People involved in the organisation of the ICM were also invited.

Dr Ramachandran, a physicist turned journalist helped the EOC with publicity for the ICM during the run-up to the Congress as well as during the Congress itself. He ran a daily bulletin for the delegates during the Congress and which carried interviews with prize winners and other distinguished mathematicians. There was extensive coverage of the Congress by the media in general.