Prime Minister Gordon Brown, clinging to power Friday after a "cliffhanger" election, is known for his dogged tenacity -- which may be crucial as he bids to keep his Labour Party in power.
Apparently seeking a deal with the Liberal Democrats to stay in 10 Downing Street, Brown maintained his usual fixed smile despite Labour's worst election showing since the 1980s.
The 59-year-old, notorious for his dour and stiff personality, was always going to struggle alongside his charismatic, younger opponents -- the Conservatives' David Cameron and Liberal Democrat Nick Clegg.
But now the premier -- who admits he is sometimes "impatient" but has denied allegations he bullied staff -- needs to show composure as well as determination while negotiations unfold.
He was born in 1951, the son of a Church of Scotland minister, and grew up in Kirkcaldy, a manufacturing town north of Edinburgh which is now in his parliamentary constituency. He says his "moral compass" comes from his father.
A bright child, he was fast-tracked through school and went to Edinburgh University aged 16, where he gained a degree and a doctorate in history. He was elected as top student leader, effectively launching his political career.
This was despite a rugby accident that left him blind in one eye and seriously limited his vision in the other.
After working as a journalist and lecturer, Brown was elected to parliament in 1983 and became friends with Tony Blair, another new lawmaker and rising star.
When then Labour leader John Smith died suddenly in 1994, Brown and Blair were frontrunners to replace him.
They agreed Blair would become Labour leader but would eventually hand over to Brown.
When Blair won the general election in 1997, he made Brown finance minister and gave him unprecedented power over domestic policy. Brown earned the nickname the "Iron Chancellor" and increased spending on public services.
But as Blair remained prime minister for longer and longer with no sign he would step aside, relations between the two came under intense strain.
Blair eventually resigned in 2007 following pressure from Brown supporters and fierce public anger over the Iraq war. Brown took over from him unopposed.
After a brief honeymoon period, Brown's popularity dived when he pulled back from calling an expected general election that October.
The following month, an opposition lawmaker summed up his fall from grace by saying he had gone "from Stalin to Mr.
Bean" -- a blundering, slapstick TV comedy character -- in a few weeks.
Brown faced plunging poll ratings, repeated attacks from his own party's lawmakers and several failed plots to end his leadership.
The credit crunch in late 2008 seemed to provide a much-needed focus for his premiership.
Although Brown's efforts were praised and imitated abroad, Britain suffered a record recession and was the last major world economy to return to growth.
Labour's popularity briefly revived due to the recovery, but then Clegg, leader of the third-placed party, shook up the election campaign with strong performances in the leaders' TV debates and Labour fell into third in opinion polls.
In the end the result of Thursday's election was a "cliffhanger," in the phrase of Brown's de facto deputy Peter Mandelson, with opposition Conservatives holding the most seats but no clear majority.
On Friday the British premier was apparently seeking to forge a deal with the Lib Dems, amid speculation that a condition for any such deal would be Brown's departure, possibly replaced by Foreign Secretary David Miliband.
Brown and his wife Sarah, a former public relations executive, have two young sons, John and Fraser. A daughter, Jennifer, died in 2002, days after being born prematurely.