West Africa.

GMT + 1.

923,768 sq km (356,669 sq miles).

130.2 million (UN estimate 2005).

140.9 per sq km.

Abuja. Population: 1.4 million (2006 census). Lagos, which was the capital until 1991, is the largest urban agglomeration with 10 million (UN estimate 2003).

Nigeria has borders with Niger to the north, Chad (across Lake Chad) to the northeast, Cameroon to the east and Benin to the west. To the south, the Gulf of Guinea is indented by the Bight of Benin and the Bight of Biafra. The country’s topography and vegetation vary considerably. The coastal region is a low-lying area of lagoons, sandy beaches and mangrove swamps, which merges into an area of rainforest where palm trees grow to over 30m (100ft). From here, the landscape changes to savannah and open woodland, rising to the Central Jos Plateau at 1,800m (6,000ft). The northern part of the country is desert and semi-desert, marking the southern extent of the Sahara.

Republic since 1963. Gained independence from the UK in 1960. Military regime from 1983-1999.

President Umaru Yar'Adua since April 2007.

Olusegun Obasanjo and the People's Democratic Party (PDP) came up for election again in April 2003. The election was a tense one since, if concluded successfully, this would be the first time since Independence that Nigeria had held two consecutive elections without military intervention. Despite allegations of widespread fraud and ballot-rigging, both the PDP and president Obasanjo were returned with comfortable majorities. (Obasanjo's main opponent was yet another ex-military dictator, Mohammed Buhari.) Obasanjo's chosen successor Umaru Yar'Adua was proclaimed victor in April 2007 in a presidential election which observers said was not credible.

The official language is English. A variation of English (Pidgin English) is also spoken. The three main Nigerian languages are Yoruba, Ibo (also spelt Igbo) and Hausa; another 400 languages are also spoken in the country.

50% Muslim (mainly in the north and west of the country), 40% Christian (mostly in the south) and 10% traditional beliefs.

240 volts AC, 50Hz. Single phase.

Shaking hands with everyone is customary on meeting and departing. In Yorubaland, it is a sign of respect for women to curtsey when introduced and to enquire after relations, even if this is a first meeting. Unless the visitor knows someone well, it is unusual to be invited to a Nigerian’s home. Most entertaining, particularly in Lagos, takes place in clubs or restaurants. A small gift of appreciation is always welcome and business souvenirs bearing the company logo are also acceptable. Casual wear is suitable and a lightweight suit and tie are only necessary for businesspeople on formal meetings; on most other occasions men will not need to wear a jacket, although a tie might be expected.

Women should dress modestly, and respect local customs regarding dress, particularly in the Muslim north. It is inadvisable for women to wear trousers. There are over 250 tribes in Nigeria, the principal groups being the Hausa in the north, the Ibo (or Igbo) in the southeast and the Yoruba in the southwest. The larger of the minor groups are the Fulani, Idoma, Igala, Igbirra, Kanuri, Tiv and Nupe in the north; the Efik, Ekoi, Ibibio and Ijaw in the east; and the Edo, Itsekiri, Ijaw and Urhobo in the west. A result of this ethnic variety is the diversity of art, dance forms, language, music, customs and crafts. Nigerians have a very strong sense of ethnic allegiance.