Beyond the prying eyes of Google and Bing exists a vast cyberfrontier — by some estimates hundreds of times larger than the World Wide Web. This so-called “deepweb” is often more humdrum than sinister, littered with banal data and derelict URLs, but it is also home to an anything-goes commercial underworld, called the “darknet,” that will make your stomach turn.

It’s a place where drugs and weapons are openly traded, where terrorists link up, and where assassins bid on contract killings. In recent years, the darknet has found itself in government cross-hairs, with the FBI and National Security Agency cracking down on drug merchants and pornographers. Despite a series of high-profile busts, however, this lawless realm continues to hum along, deep beneath the everyday web.

• Oct. 29, 1969: Charley Kline, a student at the University of California, Los Angeles, types out the first message between computers connected by ARPANET, the Internet progenitor developed by the Pentagon’s Defense Advanced Research Projects Agency. (Only the first two letters of the electronic dispatch, “LOGIN,” make it all the way to computers at Stanford University.) Within just a few years, a number of isolated, secretive networks begin to appear alongside ARPANET. Some eventually become known as “darknets.”

• 1980s: With the birth of the modern web, arguably marked by the 1982 standardization of the Internet protocol suite, the problem of storing sensitive or illegal data looms large. Early solutions involve physical “data havens” — the informational analogues of tax havens — in the Caribbean that promise to host everything from gambling operations to illegal pornography.

• Late 1990s: As the Internet goes mainstream, falling storage costs coupled with advances in file compression set off an explosion of darknet activity, as users begin to share copyrighted materials. Soon, the Internet’s peer-to-peer data transmission gives birth to decentralized data hubs, some of which, like so-called topsites — where most illegal music and movie files originate — are password-protected and known only to insiders. Others, like Napster, operate in the open and facilitate millions of file transfers per day.

• March 2000: Software developer Ian Clarke releases Freenet, revolutionary software that offers anonymous passage into the darkest reaches of the web, where one can access everything from child pornography to instructions on how to build explosives. “Freenet is a near-perfect anarchy,” Clarke tells The New York Times. “I have two words for … companies (trying to halt free file-sharing): Give up.”

• June 2000: Libertarian cyberpunks Ryan Lackey and Sean Hastings go into business on Sealand, a bizarre, nominally independent state located on a World War II-era sea fort off the British coast. The start-up, called HavenCo, envisions hosting restricted data (except spam, child porn and money-laundering activities) on high-tech nitrogen-encased servers hidden in the fort’s legs. Despite generating considerable attention, HavenCo begins to bleed money almost immediately, and by 2002, Lackey and Hastings have jumped ship.

• Sept. 20, 2002: Researchers at the U.S. Naval Research Laboratory release an early version of Tor (“The Onion Router”), which conceals the location and IP address of users who download the software. Originally designed to protect the identity of American operatives and dissidents in repressive countries such as China, Tor also has another natural constituency: denizens of the darknet.

• Jan. 2005: Wired magazine estimates that the “media darknet distributes more than half a million movies every day.” Propelled by booming bandwidth, the underground network explodes into wholesale copyright infringement, from Hollywood blockbusters to Microsoft Office. A study by IT research firm IDC estimates software piracy alone costs businesses $34 billion worldwide in 2005.

• Jan. 3, 2009: A man calling himself Satoshi Nakamoto “mines” the first Bitcoin, a form of untraceable cryptocurrency. Unlike previous digital currencies that failed because there was nothing to prevent users from literally copying their money, Bitcoin makes use of an innovative public accounting ledger that prevents double spending. Unsurprisingly, the cryptocurrency is an instant hit in the darknet, its anonymity making it a perfect tool for money laundering and criminal activity.

• 2010: The cybersecurity and intelligence firm Procysive estimates that the darknet is home to “more than 50,000 extremist websites and more than 300 terrorist forums.” The illicit sale of pirated digital content, it reports, “serves as a source of financing for (terrorist) operations.”

• June 1, 2011: A Gawker-affiliated blog publishes an exposé on Silk Road, a hidden marketplace that “makes buying and selling illegal drugs as easy as buying used electronics.” It’s like for crystal meth and LSD, except only available to Tor users with Bitcoin accounts. Traffic to Silk Road surges, and the value of a Bitcoin jumps from around $10 to more than $30 within days.

• Aug. 1, 2013: Irish authorities raid the Dublin apartment of Eric Eoin Marques, described by the FBI as “the largest facilitator of child porn on the planet.” His arrest coincides with a mysterious shutdown of vast swaths of the darknet, allegedly as part of an FBI sting operation that exploited a breach in the web browser Firefox to identify Tor users. Users’ identities are reportedly routed back to a server in Northern Virginia.

• Aug. 4: The U.S. government intercepts secret communications between al-Qaida chief Ayman al-Zawahiri and Nasir al-Wuhayshi, the head of the Yemeni-based al-Qaida in the Arabian Peninsula. The online confab leads to the shuttering of U.S. embassies in 21 countries across the Muslim world. According to researchers at the Institute for National Security Studies in Israel, the high-level al-Qaida talks “apparently took place in a part of the internet sometimes called deepnet, blacknet or darknet.”

• Oct. 1: The FBI shuts down Silk Road and arrests Ross William Ulbricht, known by his online moniker Dread Pirate Roberts, for allegedly masterminding the operation. The site did more than $1.2 billion in sales between 2011 and 2013, according to an indictment filed in U.S. federal court.

• Oct. 4: The Guardian reports that the NSA has repeatedly targeted people using Tor by exploiting vulnerabilities in other software on their computers. According to a 2007 top-secret internal presentation leaked by former NSA contractor Edward Snowden, the agency “will never be able to de-anonymize all Tor users all the time,” but with manual analysis, it can “de-anonymize a very small fraction of Tor users.”

• October: Tech-news site, the Verge, reports that online markets like Black Market Reloaded and Deepbay, both of which openly advertise narcotics, are seeing a surge in traffic. “No doubt we will all regroup elsewhere,” one Silk Road moderator wrote after the marketplace was shuttered. “I look forward to seeing all of you again … still engaging in free trade without government interference into your personal affairs.”

• November: A new anonymous darknet marketplace called Silk Road 2.0 was back online, a little more than a month after the original was shut down.

Ty McCormick is an associate editor at Foreign Policy. Foreign Policy magazine covers global politics, economics and ideas. Published bimonthly in print and daily online by the Slate Group, a division of The Washington Post Co.