He has been considered a prime minister-in-waiting for years, first being described as "the next Taoiseach" about two decades ago.
British Brexit negotiators can expect little deviation from Varadkar's hard line. Martin was a very vocal critic of Brexit and the Tory Party over the past four years. On Friday he said that notwithstanding his previous comments about the threat to Anglo-Irish relations he promised to forge close ties with the British Government.
Simon Coveney will remain as Minister for Foreign Affairs to oversee Ireland's role in the Brexit negotiations.
Sinn Fein becomes the largest party in opposition following its historic breakthrough in the general election when it came second on 36 seats. It initially pledged to form an alternative left-wing alliance government although it quickly conceded it didn't have the numbers to reach the 80 seats needed for a majority.
Fianna Fail supported Fine Gael in the outgoing government in a confidence and supply arrangement. Both parties suffered a voter backlash in the election amid a housing crisis and chaos in the health system. Fianna Fail won 37 seats while Fine Gael slumped to its worst ever result of 35 seats to lie in third place.
Social distancing rules forced MPs to abandon Leinster House for the first time and sit in the Convention Centre in Dublin docklands. Before proceedings started Mary Lou McDonald, the president of Sinn Fein, accused Fine Gael and Fianna Fail of "conspiring" to keep her party out of government. She described the coalition as a "marriage of convenience" that would ultimately fail to deliver the change demanded by voters in the election.
Fine Gael and Fianna Fail refused to hold government formation talks with Sinn Fein because of its past links to the IRA.
Even though the Green Party only won 12 seats, its manifesto heavily influenced the programme for government which is the most radical in Irish history. All offshore oil and gas exploration has been banned and there is a commitment to reduce greenhouse gasses by 7 per cent annually until 2030 – one of the most ambitious targets set by any developed country.
Martin has been an MP for 31 years and took over as leader of Fianna Fail following its worst ever election in 2011 amid the economic crisis when the party lost 57 of its 77 MPs. He secured 93 votes in favour of his nomination as Taoiseach as nine independent MPs supported his candidacy. The new Taoiseach said in his maiden speech that the incoming Government would be informed by republican ideals with "recovery and renewal" its core priorities.
"Starting today this work will be the at the very centre of everything the new Government will do," he said.
The new administration is expected to unveil next month a muti-billion stimulus package aimed at offsetting the economic downturn caused by the pandemic.
Irish business groups welcomed the formation of the new Government and said it provided the country with much needed stability.