Karlheinz Schreiber and Brian Mulroney (Jonathan Hayward, Kevin Frayer/Canadian Press)

Envelopes stuffed with cash. A secret Swiss bank account. A web of alleged deals. And a former prime minister caught in the tangle of it all.

The relationship between Brian Mulroney and German-Canadian businessman Karlheinz Schreiber dates back long before Schreiber came into the spotlight for his shady deals, here and in Germany.

But it wouldn't be until after Mulroney's nearly nine years as prime minister that allegations emerged that would eventually trigger a public inquiry.

At the heart of the issue: whether the two made a lobbying deal while Mulroney was still in office. Schreiber says they negotiated the deal two days before Mulroney left office on June 25, 1993, during a visit at the prime minister's Harrington Lake retreat in Quebec. Mulroney has always denied the claim.

Over the years, stories would come to light about the German-born Schreiber and his influence among those close to the Mulroney government.

See the following timelines for a look at their connections through the years:

• The early years: 1983-1994
• The unravelling: 1995-2006
• The investigations: 2007-2009