With the new world-leading radiotelescope LOFAR (the Low Frequency Array), Dutch scientists

are expected to detect cosmologicalradiation emitted billions of years ago, from the time of the first “stars”.This pivotal period in the history of the Universe is called the Epoch ofReionization (EoR). It holds the key to structure formation and evolution ofthe Universe we know today, but at the same time represents a missing piece ofthe puzzle in our current knowledge of the Universe. However, feeblecosmological radiation is swamped by the foreground

emission of our Galaxy and otherextragalactic radio sources. Without removing the foreground

emission from the data, we will notbe able to detect the cosmological radiation and understand the EoR. During mytalk I will give an overview of the LOFAR-EoR experiment, its challenges andpresent the most recent observational results.