At the height of the financial crisis in late 2007, many banks stopped lending to each other over concerns about their financial health with some banks submitting much higher rates than others.
Barclays was one of those submitting much higher rates, attracting some media attention. This prompted comment that Barclays was in trouble.
Following much internal debate and a controversial conversation with a Bank of England official, Barclays began to submit much lower rates. You can see this in the graph below which compares the Libor rate with those submitted by Barclays.