Article 50 gives any member state of the EU the right to exit unilaterally. The article allows for 2 years to negotiate this exit.
The relationship between Brexit and the currency exchange rate so far has been that, the closer the UK looks to agreeing a deal with the EU, the further the pound strengthens.
The pound interbank exchange rate rose against the euro, US dollar and Australian dollar in February! This is primarily because it now looks much less likely that the UK will crash out of the EU.
Sterling gained in January, as Parliament took on a larger role in Brexit. This is leading investors to hope that the UK retains ties with the EU.
The pound has strengthened, first because UK unemployment held steady at 4.0% in December, said the Office for National Statistics
The pound held its ground last week, first because the UK services sector unexpectedly slowed.
Sterling goes up, up and away versus the common currency! The pound to euro interbank exchange rate soared by +3 cents this week, at one point above 1.16, its highest since May 2017.The pound wore rocket boosters this week, because it looks likely that the UK will avoid a 'No Deal' Brexit.
Sterling has weakened, as the Bank of England warned at its latest interest rate decision that "Brexit uncertainties have intensified considerably since the [BoE's] last meeting."
Sterling sinks versus the common currency! The pound to euro exchange rate fell -0.5 cents last week, to 1.1125. The pound weakened last week, as the EU offered no new concessions to sweeten the UK's draft Brexit deal.
Sterling slides versus the common currency! The pound to euro exchange rate fell by -1.5 cents last week, to 1.125. The pound weakened last week, because Parliament may vote down prime minister Theresa May's proposed deal this Tuesday, in which it's unclear if the UK will exit the EU next March with a "No Deal".