Robbie was in Take then he wasn't then he was now he isn't again.
His debut solo single was a cover of George Michael's 'Freedom' and was released as some big statement of something other other. Unfortunately, it was a bit rubbish.
Things weren't going that well until he released 'Angels' and everyone bought it and/or had it played at their wedding/funeral.
There was a long period of time when he could do no wrong - to test this he even released a SWING ALBUM - but then he released 'Rudebox' and everyone went "hm..." in unison in spite of the fact that it was probably his best and most 'artistic' album to date.
In 2010 he re-joined Take That for the album 'Progress' and that went pretty well.