Drink-fuelled MP Nigel Evans used his "powerful" political influence to sexually take advantage of seven young men, a court heard.
The former deputy speaker, who had the "ability to make or break" careers, assaulted alleged victims in his home, House of Commons bars and his office in the Palace of Westminster, a jury at Preston Crown Court heard.
One sexual assault took place when he was "plastered" in the 'Number 10' bar at a Conservative Party Conference in 2003 when he allegedly put his hand down the trousers of his victim and the matter was referred to a senior Tory offical.
And another happened when he grabbed the penis of another young man sleeping on a sofa at his home in 2009.
He had a meeting with another Tory Chief Whip, Patrick McLoughlin and was "spoken to" and told not to put himself in such situations again.
But his behaviour "escalated" and he was not reported to police for another three years after allegedly raping another young man, the jury was told.
Evans, 56, faces nine charges in all, dating from 2002 to April 1 last year.
The MP for Ribble Valley, in Lancashire, denies two counts of indecent assault, six of sexual assault and one of rape.
Opening the case, prosecutor Mark Heywood QC said: "Within the Palace of Westminster, in his constituency and in his own political party, Mr Evans was, during the decade with which you are concerned, a very well-known and powerful individual.
"Part of his influence included the ability to make, or to break, the careers of those young people who themselves would be politicians or work for those who govern.
"The prosecution case against Mr Evans is that he, often when in drink, pressed his sexual attentions on those younger men, using or trading on his position of influence.
"Now this behaviour did not happen once but has been repeated over time and despite repeated warnings given to him by others.
"It has also escalated in seriousness, no doubt because he believed that his position made it less than likely that someone would complain."
Police began an investigation after Evans allegedly raped a 22-year-old man who spent the night at his home in Pendleton, Lancashire, last year.
Both went to sleep but the student awoke a couple of hours later when he was being raped on the bed.
Evans was said not to be "particularly aggressive or forceful" but the experience was painful for the alleged victim.
Details of the events were later passed to an MP who in turn told the Speaker, John Bercow, but did not disclose any names involved of the complainants.
The Speaker brought the matter to the attention of the police "having considered the matter, thinking it was the appropriate course to take", said the prosecutor.
The first alleged offence happened 11 years before, in late 2002, with the complainant, an openly gay man, aged 27.
The House of Commons worker was in a busy Soho bar and Evans was also there and had "obviously had quite a lot to drink," said Mr Heywood.
"Whilst the complainant was standing talking to someone else he felt a hand going down the back of his trousers.
"So you understand, there was no words, no warning or invitation.
"He was shocked by it but, and this is, you will see repeated over time, he did not want to cause a fuss because of who Mr Evans was."
The complainant was "annoyed" but "walked away" and felt "sorrow" at the MP's behaviour because while it was known he was gay, at that point he was not "openly gay" and the wider public did not know this, the court heard.
The jury heard another complainant was drinking with a friend in a bar called Number 10 at the Imperial Hotel in Blackpool during the 2003, Conservative Party Conference.
The MP was "plastered" and stood next to the complainant when ''without warning or any kind of invitation'' he tried to put his right hand into his trousers.
A member of the Conservative Party Board then stepped in and moved the defendant away from the group. But about 10 minutes later Evans returned and ''did exactly the same thing again'', said Mr Heywood.
The jury was told that it was suggested to the defendant that he was drunk and it was time to retire to bed and the young man was content for the incident to be ''quietly resolved'' by the party.
At the time Evans occupied a ''significant political job'' as Shadow Secretary of State for Wales.
The next alleged victim was a gay man, aged 21, who was interested in working in Parliament.
The MP, who appeared drunk, drew a curtain behind them on a small lobby near the Strangers Bar at Westminster and tried to kiss the young man.
''The younger man was at first shocked and said no," Mr Heywood said.
''He pushed him back and the defendant said 'oh no, it's okay' and leaned in again to kiss.
''He said 'no, it's fine but we're not doing that'.
''He felt most awkward and got out from behind him and steered the MP back towards the bar.''
Mr Heywood next outlined the fourth alleged sexual assault, in early July 2009 involving a bisexual young man and said to have taken place in Evans's house in Pendleton, Lancashire.
After drinking in the local pub they returned to the house with the complainant "very merry'' and Mr Evans ''pretty drunk''.
The MP went to bed and the younger man undressed to his boxer shorts, covered himself with a blanket and went to sleep on the sofa in the sitting room.
The younger man woke to find Evans close behind him, perched on the edge of the sofa.
Evans is then accused of putting his hand under the blanket and inside the boxer shorts of the younger man, taking hold of his penis.
''The reaction was telling,'' Mr Heywood said.
''The younger man immediately pushed the defendant across the room and screamed at him, 'What the hell do you think you're doing?'
''The defendant asked him to calm down and apologised, saying he had got carried away and he had misunderstood.''
When the young man got home he contacted Adam Price, at the time a Plaid Cymru MP, who put him in touch with Michael Fabricant, a Tory whip who told him to leave the matter with him.
A meeting was arranged with the complainant, Patrick McLoughlin MP, at the time the Opposition Chief Whip, John Randall MP and Iain Corby, managing director of the Policy Research Unit Ltd.
The young man wanted Evans to resign.
''That would be difficult,'' Mr Heywood continued, ''because at that stage in 2009, there was a general election coming and there may be local by-elections.
''It was not thought then, that was the obvious thing to happen. In the event the young man agreed.
''Mr Evans would be spoken to, he would seek help for his drinking.
''Mr Evans was spoken to. He did not deny for one minute the event. "He was given words of advice, those included that from that time on, not to put himself in situations in which allegations of this nature might arise again.''
Evans then met the younger man himself on the terrace of the House of Commons and the matter was resolved, the jury heard.
The jury heard of two more assaults, one shortly after the 2010 General Election in the Strangers Bar at the Houses of Parliament, where the complainant was drinking with Evans and others.
The pair were introduced and shook hands and engaged in ''polite conversation'' for five minutes or so.
''In that context,'' Mr Heywood continued, ''Suddenly, without warning, or invitation, or cause the defendant, Mr Evans, reached out with his right hand and physically cupped the complainant's genitals through his clothing.
''The young man pushed the hand down and away in a sweeping motion and said, 'No, that's not cool.'
Another took place when a young gay man, now aged 30, was with others drinking at bars in the Palace of Westminster in February 2011 when they were invited to go to Evans's office in the Commons.
Evans invited the man to view a new kitchen along a corridor, the court heard.
The defendant pushed the complainant into the darkened room.
"Immediately they were inside, the defendant had his hands all over the younger man saying something like 'oh you're gorgeous'," said Mr Heywood.
Evans went on to place the man's hand on his penis which led the startled complainant to dash out of the room, the jury was told.
The MP was arrested on May 4 last year and eventually charged last September.
He denies all the allegations.
The trial continues tomorrow when the alleged victims begin to give their evidence.