Alex Carlile, the son of Polish Jewish immigrants,[2] was born in Ruabon, Wrexham, Wales and brought up in Lancashire.

Carlile was appointed Commander of the Order of the British Empire (CBE) in the 2012 New Year Honours for services to national security law.

At the 1983 election, standing as a Liberal Democrat, he became the Member of Parliament for Montgomeryshire and held the seat until 1997; he also became the leader of his party in Wales.

[7] Carlile sat as a Liberal Democrat peer until 2016, when he left the party, stating that he found himself "at odds" with its policies on many matters, including national security issues.

He is a Honorary Doctor of Laws in the Universities of Swansea, South Wales, Chester, Manchester Metropolitan, and the Hungarian Institute of Criminology.

[13] In 2016 Carlile sat on the founding committee of National Opposition to Windfarms, and sponsored the launch event at the Houses of Parliament.

[18] In 2015, he joined with a cross-party group of peers to reintroduce the Draft Communications Data Bill, known by its opponents as the "Snoopers' Charter".

[20] He was vocal in his opposition to the UK coalition government's Legal Aid, Sentencing and Punishment of Offenders Bill, proposing many amendments.

[27] On 11 July 2018, Carlile (after being granted a visa) was refused entry to India at Indira Gandhi International Airport where he was due to address a press conference in defence of jailed Bangladeshi politician Khaleda Zia and meet a human rights body.