Finance minister Brian Lenihan called the National Asset Management Agency (Nama) the biggest financial decision in the history of the state. In a few days' time, the first of the €80bn or so in property loans, spreading from half-built offices in Dublin to holiday homes in Dubai, will be transferred to the agency.

Charged with ensuring that the agency recoups the €54bn it is paying to rid the banks of their toxic property loans is a handful of individuals from the public and private sector. The decisions they make in the next few years will determine if Nama makes good on its business plan forecast of generating a profit of nearly €5bn when it is finally wound up.

Chief executive of Nama, and now arguably the most powerful public servant in the country, is Brendan McDonagh. Trinity-educated McDonagh (41) joined the National Treasury Management Agency (NTMA) in 1994 after a stint in the ESB and worked in its finance department, first as financial controller and then as a director of finance, technology and risk. From Killorglin in Kerry, he was appointed interim head of Nama in May 2009 a month after Lenihan announced plans to set up the agency. His salary has yet to be disclosed but he is likely to be among the best paid public servants in the country.

"He was a backroom guy, but hugely competent," says one person who has dealt with the NTMA for more than a decade. "He's well liked in there and he wouldn't be one to throw his weight around. It's clear he's very bright, so you could see why Brian Lenihan appointed him."

So far, McDonagh has made just a couple of public appearances: before a Dáil committee and a presentation to a UCD-organised legal conference. But those that have met him in Nama preparation meetings said his knowledge of the property and banking sector has been impressive and said he has been tough in his dealings with the banks.

"He's been very meticulous.He's making sure he goes through all the loan documentation line-by-line and making sure the banks have provided Nama with everything," said another individual who has met with McDonagh several times.

The tough stance was evident from his first appearance before a Dáil committee last year when he said Nama wouldn't be an easy ride for property developers and that borrowers would "still owe Nama the full amount they originally borrowed from the banks and there is no question of a bailout for any borrower".

McDonagh will report to Frank Daly, who was appointed Nama chairman by Lenihan in late December. Daly was called out of retirement by the government to take on several high-profile roles. He was appointed a non-executive director of Anglo Irish Bank and chairman of the Commission on Taxation. Daly spent more than 40 years with the Revenue Commissioners and was chairman from 2002 to his retirement in 2008. Daly will be paid about €170,000 a year, the largest salary to be paid to the chair of a state agency.

"I think Frank Daly is the model of a senior public servant. He was responsible for modernising Revenue and also for the investigations into various tax evasion schemes. Any time I questioned him at a Dáil committee I thought he was very open," said a senior political figure.

Under Daly, Revenue expanded its investigations into tax evasion, launching trawls for hidden offshore assets, which netted nearly €1bn in uncollected taxes and fines. He was also behind the investigation of single premium insurance policies, which pulled in more than €460m and the conclusion of Revenue's Dirt inquiry.

Also closely involved in Nama and a director of the agency is John Corrigan. He took over as chief executive of the NTMA when Michael Somers retired. Corrigan, a former head of AIB Investment Managers, was one of the NTMA's first appointments when it was set up in 1991 and ran the National Pension Reserve Fund (which comes under the NTMA's remit), prior to succeeding Somers.

"John is an old hand and he was a natural successor to Michael. If Adrian Kearns [a former NTMA executive who is on the board of Irish Nationwide] had stayed on he might have got it but it was down to the two of them," said a person who has been involved with the NTMA for some years. "He's fairly tough and won't take guff from anybody. He would have been very close to Michael. He hasn't moved into Michael Somers' office yet."

Although he is not on the Nama board, John Mulcahy wields huge influence at the agency. The former chairman of the Irish arm of American property firm Jones Lang Lasalle, Mulcahy was drafted by Lenihan to assist the Department of Finance and the NTMA on setting up Nama. Mulcahy was an adviser on some of the biggest property deals in the country at the height of the boom, including the sale of the former Irish Glass Bottle factory site in Ringsend, Dublin, to the Dublin Docklands Development Authority and Bernard McNamara. It was not surprising the 61-year-old was given an ongoing role in Nama. As head of portfolio management he will have control over what developments will get the green light and which will be shelved.

Northern Ireland banker Ronnie Hanna has been parachuted in to the role of head of credit and risk. He has spent 30 years with Ulster Bank in Belfast in various roles, including head of risk for the lender in Northern Ireland.

Outside of the day-to-day running of the agency, the Nama board is a mix of accountants and bankers who were chosen from a pool of 800 people who applied for the non-executive director posts.

Bringing heavyweight international experience to Nama is Stephen Seelig, who works in the Monetary and Capital Market Department at the International Monetary Fund in Washington. Seelig was part of the IMF delegation that visited Ireland in 2009 and while he gave his backing for Nama he said he didn't believe it would result in a significant increase in bank lending. He joins the board in May.

Financial expertise is brought by Michael Connolly, a former Bank of Ireland executive, and Eilish Finan a former finance chief of AIG Global Investments. Also on the board is Limerick-based Brian McEnery from accounting firm Horwath Bastow Charleton and a specialist in corporate recovery and Patrick Stewart, managing director of accountants O'Donovan Stewart & Company. Willie Soffe, the former Fingal county manager and chairman of the Dublin Transportation Office is also on the board. They will get about €50,000 for the part-time roles.