MPs returned to the House of Commons on Tuesday afternoon and saw John Bercow re-elected unopposed as Speaker.
Mr Bercow told MPs: "We appear to be destined for testing times, I offer myself to the House as a tested Speaker."
The Buckingham MP added he will ensure all parts of the House are heard "fully and fairly", with the rights of backbenchers championed in order to hold the Government to account.
The 54-year-old had been expected to face a challenge if the Conservatives had secured an increased majority after the General Election, but the loss of Tory seats saw the party lose its majority and forced opponents of Mr Bercow to back down.
Representatives of all the political parties represented in Parliament gave speeches, all opening by praising the emergency services for their responses to the Manchester and London Bridge terror attacks which took place while Parliament was dissolved while election campaigning took place.
They noted that while terror attacks seek to divide people, the response of the UK has been to come together.
During their speeches, both Theresa May and Jeremy Corbyn drew laughs from the chamber - which was completely filled with many MPs left standing or sat on the floor - as both made jokes at the Prime Minister's expense.
Mrs May praised Mr Bercow's re-election, telling him: "At least someone got a landslide".
In a more serious note she continued: "May I also congratulate you on being the first speaker since the Second World War to be re-elected three times.
"In your tenure so far you have been a great champion of backbenchers, ensuring that every member of this House has the opportunity to speak and to be heard in representing the people they serve.
"This is such an important part of the way our democracy is upheld in this House and I know you will continue in this vital role in the future, just as you have in the past."
The Prime Minister also praised the fact that at the June 8 vote, more than 200 female MPs had been elected, the most in any Parliament.
She added: "While there is further to go, if there is one outcome from this election we can all welcome, it is surely this, that today we have the most diverse and representative parliament in our history."
Mrs May also praised the appointment of Tory MP Ken Clarke as Father of the House, a title bestowed on the most senior MP with the longest continuous service, paying tribute to his "long and distinguished career".
The Tory leader also broke with tradition by welcoming Labour's Harriet Harman as the "Mother of the House", for the longest unbroken service for a female MP.
Continuing with her theme of unity, Mrs May also called on MPs to "come together in a spirit of national unity", urging them to recognise "we all want to see a Britain that is stronger, fairer and safe and secure for our children and grandchildren...
"As we face difficult challenges ahead, let us come together in a spirit of national unity to keep our country safe and build a stronger, fairer, and more prosperous future for everyone in every part of our United Kingdom."
Mrs May said it was "clear that our country faces some of the greatest challenges of our time" as the new parliament begins, including keeping the "nation safe", "securing the best possible Brexit deal" and "spreading opportunity and prosperity to every part" of the country.
"In meeting these challenges, what we have seen from the election is that there are parts of our country that remain divided - divided between young and old, rich and poor, those for whom the future offers a sense of opportunity and those for whom it brings worry and concern.
"Some people blame politics for these divisions or say there is too much politics, but politics can be an incredible force for good - conducted in the right way it can be how we resolve our differences, how we deal with injustices and how we take, not shirk, the big decisions.
"It's not always glamorous or exciting but, at its best, the duty we share as politicians to serve others in confronting these challenges is a truly noble calling for us all, and the test for all of us is whether we choose to reflect divisions or help the country overcome them."
When Jeremy Corbyn entered the Commons he received a standing ovation from Labour MPs, and wearing a large red rose on his lapel, he went on to deliver an enthusiastic speech littered with jibes at the Prime Minister's expense.
As is customary for the Leader of the Opposition, Mr Corbyn congratulated Mrs May on returning as Prime Minister, before adding "democracy is a wonderous thing and can throw up some very unexpected results".
The 68-year-old then went on to use the Conservatives' election slogans against them, making light of the Prime Minister's bid to agree a deal with the to prop up her Conservative administration, declaring: "We all look forward to welcoming the Queen's Speech just as soon as the coalition of chaos has been negotiated....
"If that's not possible the Labour Party stands ready to offer strong and stable leadership in the national interest."
The MP for Islington North continued that he "looked forward to the new Parliament" before adding: "however long it may be".
Mr Corbyn also praised the appointment of Tory MP Ken Clarke as Father of the House of Common, recalling his first sighting of the Rushcliffe MP in 1983 when he saw him eating bacon, drinking lager and smoking a cigar, all during a break during a debate on healthy living.
The Labour leader also welcomed new members to the House of Commons and praised Mr Bercow's re-election, highlighting the way in which the Speaker travelled around the country visiting schools in a bid to engage people in politics.
Similarly to Mrs May, Mr Corbyn also praised "the most diverse House of Commons ever", paying particular tribute to fellow Labour MPs Diane Abbott and Keith Vaz for having "paved the way" and "put up with an awful lot" since taking their seats in 1987.
He continued: "This weekend marks the anniversary of the election of four black MPs to the House of Commons 30 years ago, the first black MPs for more than 60 years in the British Parliament...
"It's vital for our democracy that all voices are heard and represented."
Democratic Unionist Party MP Nigel Dodds, whose party the Tories want help from in order to govern, said his colleagues "bear a heavy responsibility" in the Commons.
He added: "We intend to carry out that responsibility very, very carefully indeed.
"We hope, of course, for the restoration as soon as possible of our locally-devolved assembly and executive in Northern Ireland, where everybody can play a part in the Government of Northern Ireland.
"So, we have interesting times ahead, I look forward to playing a full role in the proceedings of this Parliament over the course of the next five years and I wish (Speaker John Bercow) well in your office during that time."
Acting SNP Westminster leader Stewart Hosie lamented the "big beasts" who lost their seats at the General Election, adding "we may miss them sooner rather than later".
The MP for Dundee East added that politics was "not divisive", merely a difference of opinion.
As did all the other speakers, Liberal Democrat leader Tim Farron praised the country's response to the recent terror attacks saying: "They were outrages that were meant to divide us and our response is to be united, to show love and respect, and immense gratitude for those who came to our aid."
MPs will begin the process of swearing-in from 2.40pm on Wednesday. This enables them to formally take their seats in the Commons.