Silas Ramsbottom is the director of the Anti-Villain League (or "AVL"), an agency "devoted to fighting crime on a global scale".  Silas orders junior AVL agent Lucy Wilde to recruit Gru to help find out which supervillain stole the very dangerous mutagenic PX-41 serum, and assist in his capture and the serum's safe return. 

Silas is a bit of a stuffed shirt, however (and somewhat overweight as well)...a classy British gentleman who has little patience or tolerance for active or former supervillains (including Gru), and who will stop at nothing to see the AVL bring its every mission to a successful conclusion, regardless of the cost or consequences.  Even regardless of how accurate and reliable their methods happen to be.  And typical of a British gentleman, he prefers tweed suits and afternoon tea, even having his own butler to attend to his needs.

However, like all super spies, and in spite of his obvious physical limitation, Silas is not to be underestimated, and likely has a wealth of discreet weapons at his immediate disposal.