(Reuters) - Valeant Pharmaceuticals International Inc (>> Valeant Pharmaceuticals Intl Inc) (>> Valeant Pharmaceuticals Intl Inc), which has been under scrutiny over its pricing and accounting practices, cut its 2016 sales and earnings forecast on Monday, and said a delay in filing its annual report put it in danger of a default on its $30 billion debt.

The past few months for the troubled Canadian drugmaker have also put a question mark over its overall strategy of rapid acquisition-driven expansion and aggressive price hikes.

Following is a summary of key events in Valeant's history:

December 2007: Biovail Corp of Canada, Valeant's predecessor, pays $138 million to settle a shareholder lawsuit accusing it of making false statements to inflate its stock price.

February 2008: California-based Valeant Pharmaceuticals International names McKinsey & Co veteran and pharmaceutical acquisitions expert Michael Pearson as its CEO. It buys Coria Laboratories for $95 million and Australia's DermaTech for $12.6 million that year.

March 2008: The U.S. Securities and Exchange Commission charges Biovail Corp, its former CEO, and three other senior executives with fraudulent accounting and making a series of misstatements to analysts and investors.

January 2009: Valeant buys Dow Pharmaceutical Sciences Inc, a maker of topical dermatology products, for $285 million and buys Mexican generic drugmaker Tecnofarma.

May 2010: Valeant buys Aton Pharmaceuticals, a New Jersey-based maker of ophthalmology products, for $318 million.

Sept 2010: Valeant is acquired by Biovail in a reverse merger. Pearson becomes CEO of the combined company with an annual revenue of $1.75 billion. It takes Valeant's name and is incorporated in Canada, where Valeant predicts to have a 10-15 percent tax rate, far below the U.S. levels.

2011: Valeant settles a civil lawsuit brought by the SEC accusing Biovail of accounting fraud. It boosts its presence in Central and Eastern Europe by snapping up Switzerland-based generic company PharmaSwiss for $481 million; AB Sanitas of Lithuania for about $500 million; Canada's Afexa Life Sciences and Sanofi SA's dermatology unit Dermik. However, its $5.7 billion unsolicited bid for U.S. biotech Cephalon loses to an almost $7 billion offer from Israeli drugmaker Teva Pharmaceutical Industries.

2012: Valeant buys Medicis Pharmaceutical Corp for $2.6 billion, acquiring anti-wrinkle medicines and facial fillers that compete with Allergan Inc's (>> Allergan, Inc.) market-leading portfolio.

April 2013: Valeant offers more than $13 billion in stock for smaller U.S. rival Actavis Inc, but merger talks collapse.

August 2013: In its biggest deal ever, Valeant buys eye-care company Bausch & Lomb from private equity firm Warburg Pincus for $8.6 billion.

January 2014: After making the list of world's top 15 drugmakers by market capitalization, Pearson tells analysts Valeant aims to crack the top 5 by the end of 2016.

March 2014: Jim Grant, editor of an investment journal, criticizes Valeant for its lack of concern for research and development.

April 2014: Valeant and activist investor William Ackman's Pershing Square Capital Management hedge fund team up to buy Allergan.

May 2014: Bronte Capital's John Hempton says his fund is shorting Valeant, calling its accounts "difficult to comprehend". James Chanos, founder of Kynikos Associates and short on Valeant accuses it of "aggressive accounting games".

June 2014: Allergan, battling off Valeant's takeover attempt, releases email exchanges with Morgan Stanley in which the bank called Valeant a "house of cards."

Nov 2014: Valeant and Ackman end their pursuit for Allergan after rival Actavis outbids them with a $66 billion offer.

March 2015: Pershing Square discloses it has taken a 5 percent stake in Valeant.

April 2015: Valeant completes its $11 billion purchase of Salix Pharmaceuticals, a maker of gastrointestinal medicines.

June 2015: Long-time investor ValueAct Capital Management says it sold 4.2 million Valeant shares, but retains a stake worth over $3 billion.

Sept 28, 2015: Democratic members of a Congressional committee urge their chairman to subpoena Valeant over "massive" price increases for two of its heart drugs.

Oct 15, 2015: Valeant says it has been subpoenaed by U.S. prosecutors seeking details on its patient assistance programs, drug pricing and distribution practices.

Oct 19, 2015: New York Times reports how Valeant has used its ties with a specialty pharmacy Philidor to sell conventional medications, averting health insurer barriers to reimbursement.

In a conference call later that day, Valeant discloses for the first time that it has used Philidor's services, has an option to buy the pharmacy and has already incorporated its financials into its own results.

Oct 21, 2015: Valeant shares plunge as much as 40 percent after an influential short-seller, Citron Research, accuses the company of using specialty pharmacies, including Philidor, to inflate its revenue. Valeant categorically denies the allegations.

Oct 26, 2015: Valeant holds investor call to defend itself against Citron's allegations and sets up an ad-hoc committee to study them in depth.. Valeant shares end 5.3 percent down.

Oct 30, 2015: Valeant cuts ties with specialty pharmacy distributor, Philidor, accused of helping it inflate revenue. Philidor has since gone out of business. Valeant later warned its dermatology business would be hurt in the short term.

Dec 15, 2015: Valeant inks a deal to distribute its drugs through pharmacy chain Walgreens Boots Alliance Inc (>> Walgreens Boots Alliance Inc).

Dec 16, 2015: The Canadian drugmaker says its Q4 profit was hit when it cut ties with pharmacy Philidor Rx Services, but it could contain the damage in 2016 and grow profit.

Dec 28, 2015: Valeant appoints group of company executives to take over duties of its Chief Executive Michael Pearson until he returns from medical leave.

Jan 6, 2016: The company appoints its former CFO Howard Schiller as interim CEO.

Jan 28, 2016: Campaign of Democratic presidential contender Hillary Clinton posts a blog detailing exorbitant price hikes for a migraine drug made by Valeant.

Feb 4, 2016: At a U.S. congressional hearing interim CEO Howard Schiller puts forward a conciliatory face, testifying that his company had changed its business and pricing tactics.

Feb 22, 2016: Valeant says it would restate its financial results for 2014 and 2015 after identifying some sales of Philidor that should have been recognized when products were dispensed to patients.

Feb 29, 2016: Valeant discloses that it was under investigation by the U.S. Securities and Exchange Commission a day after announcing the return of CEO Pearson from medical leave and withdrawing 2016 guidance.

March 7, 2016: Valeant says it would release preliminary quarterly results and guidance on March 15, two week after it was originally scheduled to be released.

Mar 9, 2016: The company adds a representative from shareholder Pershing Square Capital Management to its board as well as two other new directors.

Mar 10, 2016: A U.S. congressional committee urges Valeant to explain why it was withholding documents related to an investigation into steep hikes in prices of two of the company's heart drugs.

Mar 15, 2016: Valeant cuts 2016 revenue forecast by about 12 percent and says a delay in filing its annual report could mean a debt default, causing its shares to plunge.

Sources: Reuters, Valeant press statements

(Reporting by Ransdell Pierson in New York and Amrutha Penumudi in Bengaluru; Editing by Tomasz Janowski)