Article continues below advertisementKate Middleton was secretly a key driving force behind the final removal of Andrew Mountbatten Windsor's royal titles, senior palace sources have claimed - with insiders describing her approach as "calm, determined, and utterly relentless."The 43-year-old future queen is said to have urged King Charles III to act decisively to protect the reputation of the monarchy and her young family from further scandal.Article continues below advertisementSource: MEGAKate Middleton apparently was central to removal of ex-Prince Andrew's titles, a source said.