Complex sentence: He was also Luxembourg's Minister for Finances from 1989 to 2009 and the first permanent President of the Eurogroup from 2005 to 2013, his tenure encompassing the height of the European financial and sovereign debt crisis.
Split into simpler sentences: He was also Luxembourg's Minister for Finances from 1989 to 2009. His presidency, lasting from 2005 to 2013, encompassed the height of the European financial and sovereign debt crisis.