Two years ago on Diwali, Rishi Sunak, then chancellor of the exchequer, lit lamps outside the door of No 11 Downing Street in London. This week he can do the same outside No 10, but as Prime Minister of the United Kingdom.

It is a fine and remarkable achievement for the 42 year old, who is also the youngest British prime minister in nearly 200 years. His economic expertise, integrity, professionalism and reputation for hard work may restore the credibility of the government. He will be their third prime minister this year and by and large the country had despaired of the chaotic rule of Boris Johnson, and the wild economics of Liz Truss, which saw the pound sterling tumble on the international money markets at the end of September.

Rishi Sunak holds a first class degree in politics, philosophy and economics from Oxford university, and an MBA from Stanford, which he achieved via a Fulbright scholarship and where he met Akshata Murthy whom he later married. He worked for Goldman Sachs and then two hedge funds in London before entering parliament in 2015. He was made chief secretary to the Treasury under Sajid Javid, then chancellor, in 2019. He is both a skilled technocrat and a politician.

What Sunak shares with Javid is Punjabi roots in today’s Pakistan. Rishi Sunak’s paternal grandfather, Ramdas Sunak, left Gujranwala in 1935 for a job in the colonial service in Nairobi. He was followed two years later by his wife, Subag Rani Sunak. Of their six children, Rishi Sunak’s father Yasheer left Kenya for the UK in 1966 to become a doctor. Here he met and married Usha Berry, whose Punjabi family had settled in Tanzania.

Rishi Sunak assumes the role of UK prime minister at a time of global difficulties and uncertainties, and not least massive climate change. In Pakistan this has created devastating floods, disease and poverty; £5 million was donated by the UK government to help with the floods, a further £25 million has been raised by the British public via the Disaster Emergency Committee.

At home, there is a £40 billion deficit in the UK economy, the result of losing the EU as a major trading partner following Brexit, the economic inactivity of the Covid pandemic and slow and uncertain growth in the world economy.

Above all Sunak believes in a liberal international order and free trade, which includes vibrant diplomacy.

But at heart, his appointment as prime minister has many significant layers. It is this year the seventy-fifth anniversary of Partition and the searing division of Punjab and Bengal. Throughout the Raj, it was these states - their fierce intellectual life and resilience - that proved the greatest challenge to the British.

Fittingly, on the full moon of Diwali the brilliance of the subcontinent is remembered. Rishi Sunak, whose family came from Punjab, is the UK’s prime minister.

Full disclosure: the writer does not vote Conservative or belong to the Conservative party.