2004–2005: Greatest Hits and Remix album

After her marriage to Kevin Federline, Spears announced via her website she would be taking another career break in order to start a family. 2004 saw the release of her first greatest hits collection, Greatest Hits: My Prerogative. The album debuted at number four on the U.S. charts selling over 255,000 copies and featured three new songs, including her version of Bobby Brown's 1988 hit My Prerogative which became a modest hit. The compilation included all of her singles except for From the Bottom of My Broken Heart, which is not included in any edition.

In November 2005, Spears released a remix album, B In The Mix: The Remixes. The album contained remixes of Spears's biggest hits, ranging from ...Baby One More Time to Toxic. It also included a remix of her newest single Someday (I Will Understand), originally a piano ballad that was an ode to the then-unborn Sean. A new song, And Then We Kiss, was only released in Asia, where it charted well in several countries. The song appeared on Billboard's Hot Dance Airplay chart and peaked at number 15, despite the fact it was only for digital download and not officially released in the U.S. Without any marketing from Spears, the album itself was not a commercial success, only peaked at number 134 on the Billboard 200.