Election results 2017: Labour gain Reading East
Labour have dented the Conservative dominance in Berkshire.
Reading East, which has been held by Tory Rob Wilson since 2005, fell to Labour's Matt Rodda with a 9.8% swing.
In Slough, new MP Tan Dhesi increased Labour's share of the vote by 14.4% and became the UK's first turban-wearing Sikh MP.
Conservative MPs were re-elected in Reading West, Maidenhead, Windsor, Bracknell, Newbury and Wokingham.
In a bruising night for the Tories nationally, the party suffered its most damaging Berkshire loss in Reading East.
Labour's Matt Rodda won that - with a majority of 3,749 - overturning Conservative Rob Wilson's previous 6,520 majority.
Mr Rodda said he was "a bit surprised" by his victory and believes Labour "set a new tone for politics in the south" during the election campaign.
However, in neighbouring Reading West, Conservative Alok Sharma held off the Labour challenge and won with a reduced 2,876 majority.
Slough had been a target seat for the Conservatives but Labour's Tan Dhesi held the seat with an increased 16,998 majority.
When asked by the BBC how he felt to be the first turban-wearing Sikh MP, Mr Dhesi said he was "proud and honoured".
"It is a great honour and privilege to serve the town where I was raised," he added.
Elsewhere, Prime Minister Mrs May retained her Maidenhead seat with a 26,457 majority.
Despite her party's disappointing results elsewhere, she said: "My resolve this morning is the same as it always has been."
In Bracknell, Labour almost doubled its share of the vote. However, Conservative Dr Phillip Lee still prevailed with a 16,016 majority.
Dr Lee said the Conservatives now needed to examine why they were "not appealing to young voters".
Former secretary of state for Wales John Redwood held Wokingham with a 18,798 majority, while Richard Benyon won with a 24,380 majority in Newbury.
In Windsor Adam Afriyie held Windsor for the Tories with a 22,384 majority.