Nigeria’s President Muhammadu Buhari on Wednesday swore in a new cabinet, three months after starting his second term as leader of the country with Africa’s biggest economy.

Here are some of the key figures in the government led by the 76-year-old former military ruler:

TIMPIRE SILVA – PETROLEUM MINISTER

As minister of state for petroleum, Timpire Silva holds arguably the most powerful ministerial post outside of the presidency due to the key role played by oil in Africa’s largest economy.

President Muhammadu Buhari opted to keep the portfolio of petroleum minister for himself, just as he did in his first term. Buhari took a largely hands-off approach and left Silva’s predecessor – former ExxonMobil executive Emmanuel Kachikwu – to oversee the ministry.

He is widely expected to maintain that approach, which would see Silva represent Nigeria at OPEC meetings and oversee the ministry.

Silva is a veteran of politics in the southern oil-producing Niger Delta region, having served as governor of Bayelsa state in 2007 and as an elected official in the Rivers State House Assembly in the early 1990s.

Prior to his elevation to the cabinet, Silva chaired the governing board of the Oil and Gas Free Zone Authority, a national regulatory body set up to foster public-private partnership investments in Nigeria’s oil and gas free zones.

ZAINAB AHMED – FINANCE MINISTER

Zainab Ahmed was promoted to finance minister in the latter stages of Buhari’s first term, in September last year, having previously served as the junior minister for budget and national planning.

Prior to entering the government, Ahmed burnished her anti-corruption credentials as head of the Nigeria Extractive Industries Transparency Initiative (NEITI). She occupied that role from 2010 until her appointment in 2015 at the budget and national planning ministry.

Ahmed did not deviate from the policies put in place by her predecessor, Kemi Adeosun. And she has signalled that she is unlikely to plot a different course in the near future.

In April, she said Nigeria had no intention of removing costly subsidies on petroleum products after the International Monetary Fund (IMF) advised the country to eliminate them to protect public finances.

Unlike Adeosun, whose role was only that of finance minister with no responsibility for the budget, Ahmed’s role encompasses budget and national planning with the merger of previously separate ministries.

BASHIR MAGASHI – DEFENCE MINISTER

Addressing multiple security problems in Nigeria is one of the main priorities of Buhari’s second term.

In Magashi, Buhari has selected a retired major general who is just two years his junior. The hope is that Magashi’s military background will help with the fight in the northeast against Boko Haram insurgents and militants with ties to Islamic State.

Magashi started his military career as a second lieutenant in 1968. He also served as the commander of a brigade in the northwestern state of Sokoto.

Buhari once referred to himself as a “converted democrat”.

Just as he pursued a career in politics after the military, Magashi also entered politics after retiring as a major general in 1999 and unsuccessfully ran for governor in the north’s commercial hub, Kano state, in 2007.

OTUNBA ADEBAYO – INDUSTRY, TRADE AND INVESTMENT MINISTER

Otunba Adebayo takes control of the trade and investment ministry at a time when Nigeria will need to overcome the apparent inconsistencies of its protectionist policies and being a signatory to the African Continental Free Trade Agreement.

His ministry will also seek to attract new investment after currency controls and multiple exchange rates, in place since 2015, prompted many overseas investors to flee.

Adebayo, whose first career was as a lawyer, is steeped in Nigerian politics. He was deputy national chairman of Buhari’s ruling party in the south of the country. And, prior to that, he was elected governor of southwestern Ekiti state in 1999.

He has replaced one of the few technocrats in Buhari’s first cabinet. Okechukwu Enelamah, Adebayo’s predecessor, was a private equity investor Lagos who co-founded investment and financial advisory firm Africa Capital Alliance.

Analysis by REUTERS