Complex sentence: Under Fico, the most popular politician in the country, it quickly surpassed the SDĽ and absorbed it and other centre-left parties in 2005 and adopted its current name.
Split into simpler sentences: Under Fico, at the time one of the most popular politicians in the country, it quickly surpassed the SDĽ. In 2005, it absorbed SDĽ and several other centre-left parties and adopted its current name.