An Islamic State-inspired terrorist plotted attacks in the UK on a range of targets including Big Ben and the Queen's Guard, a court heard.
Umar Haque, 25, allegedly enlisted the help and support of others at his local mosque where he also tried to groom children with roleplay and extremist videos.
Opening his Old Bailey trial, Mark Heywood QC said: "The essence of this case is that the first defendant Umar Haque had decided in 2016 and early 2017 to carry out one or more violent attacks with others if he could in this country.
"His motivation was the same motivation that drives the banned Islamic State group and was at its heart religious and political.
"He hoped in due course to be able to inspire others to join him in one or more than one significant violent attacks on targets in this country including on both civilian, police and other targets."
Abuthaher Mamun, 19, Muhammad Abid, 27, and Nadeem Patel, 26, who knew Haque through the Ripple Road Mosque in Barking, east London, are accused of helping him in various ways.
Mamun assisted with planning and details, Abid had a role in "discussion and lower level of support" while Patel agreed to provide a gun, jurors were told.
Mr Heywood said: "Umar Haque was fascinated by the warped and extreme ideology of Islamic State.
"He had identified methods and targets. Those targets were numerous but included for example, the Queen's Guard, the courts, Transport for London, Shia Muslims, Westfield, banks in the City of London, Heathrow, west London, Parliament, Big Ben, the English Defence League or Britain First, embassies, media stations.
"Mamun also agreed to, and set about, raising money to fund Haque's plans."
Haque and Mamun are accused of preparing acts of terrorism between March 25 and May 18 2017.
Haque is accused of researching and planning a terrorist attack while Mamun allegedly traded in options in order to finance it.
Haque is further charged with preparing terrorist acts by leading exercises in physical training and "role play" with children at the Ripple Road Mosque.
Religious teacher Haque is further accused of dissemination of terrorist publications.
Abid is accused of having information about Haque's plans and Patel is charged with plotting with Haque to possess a firearm or imitation firearm.
The defendants, who all lived in east London, have denied the charges.
Haque has admitted charges of collection of terrorist information and a further charge of dissemination of a terrorist publication.
And Patel has admitted possessing a prohibited weapon.