The FTSE 100 continued its recent surge of optimism to jump over the 6,000 points mark for the first time in seven weeks, since before the UK felt the full impact of coronavirus.
Positive news regarding drugs trials and the easing of lockdown restrictions spurred traders across the continent.
The FTSE 100 closed 156.75 points higher at 6,115.25p at the end of trading on Wednesday.
David Madden, market analyst at CMC Markets UK, said: “European stock markets (moved) higher as traders are optimistic that lockdowns could be loosened.
“Some countries have reopened small parts of their respective economies, and there is a general feeling in the markets that we are likely to see more of this in the months ahead.
“Traders are also bullish on stocks due to a report that showed some progress had been made in relation to a possible treatment for Covid-19.”
In the US, the markets were stoked by reports that Gilead Science’s antiviral drug, Remdesivir, showed “positive data” in a trial.
The Dow Jones soared as a result while the major European markets all pushed towards figures last seen in early March.
The German Dax increased by 2.89%, while the French Cac moved 2.22% higher.
Meanwhile, sterling nudged higher against the weak dollar, which was dented by news that the US economy contracted by 4.8% in the first quarter.
The value of the pound rose 0.08% versus the US dollar at 1.243 and was down 0.22% against the euro at 1.145.
Banking stocks pushed higher in London as solid quarterly updates from Barclays and Standard Chartered helped to support positive sentiment.
Barclays rose towards the top of the FTSE despite profits at the bank falling by more than 42% in the first three months of the year.
Barclays boss Jes Staley said the bank had “a good quarter” until Covid-19 hit its business. It closed 12.42p higher at 110.18p at the end of trading.
Standard Chartered shares increased after the lender vowed to come through the Covid-19 pandemic “with strength”, despite a sharp drop in first-quarter profit.
In the three months to March 31, the Asia-focused bank’s pre-tax profit plunged 29% to 886 million US dollars (£712 million) from the same period a year earlier. Shares increased 45.1p to 435p.
Elsewhere, Next moved higher despite warning that the impact of the coronavirus lockdown on trading has been “faster and steeper” than expected.
The chain – which reopened for online trading on April 14 – reported a 41% plunge in full-price sales over its first quarter to April 25. Shares rose 189p to 4,975p.
Dixons Carphone shares surged ahead after revealing booming online trading recovered around two-thirds of stores sales lost amid the lockdown. It closed 12.45p higher at 80.95p.
The price of oil jolted higher on the back of two energy inventory reports in the past day, with the latest EIA update showing that US oil stockpiles grew by 8.99 million barrels.
The price of a barrel of Brent crude oil increased 9.7% to 22.8 US dollars.
The biggest risers on the FTSE 100 were Carnival, up 164.1p at 1,160.5p, Centrica, up 5.53p at 41.45p, Barclays, up 12.42p at 110.18p and Evraz, up 31.1p at 278p.
The biggest fallers of the day were Polymetal, down 28p at 1,646p, Ocado, down 26.5p at 1,625p, Croda, down 42p at 4,936p, and RB, down 52p at 6,402p.