▁Battle ▁of ▁Zur ich ) ▁he ▁was ▁act ively ▁employed ▁under ▁Dum our iez , ▁P iche gru , ▁More au , ▁Mass é na , ▁and ▁others . ▁ ▁Early ▁Empire ▁In ▁ 1 8 0 3 , ▁he ▁was ▁colon el ▁of ▁the ▁ 5 th ▁regiment ▁of ▁horse ▁art illery , ▁and ▁refused , ▁from ▁political ▁principles , ▁the ▁appointment ▁of ▁a ide - de - camp ▁on ▁Napoleon ' s ▁assumption ▁of ▁the ▁imperial ▁throne . ▁Nevertheless , ▁he ▁was ▁employed ▁in ▁August e ▁Mar mont ' s ▁II ▁Corps ▁and ▁shared ▁in ▁the ▁vict ories ▁of ▁Napoleon ' s ▁brilliant ▁ 1 8 0 5 ▁Ul m ▁Camp aign ▁in ▁Germany . ▁ ▁In ▁ 1 8 0 6 , ▁he ▁commanded ▁the ▁art illery ▁of ▁the ▁army ▁station ed ▁in ▁Fri uli , ▁for ▁the ▁purpose ▁of ▁occup ying ▁the ▁Ven et ian ▁territory ▁incorpor ated ▁by ▁the ▁treat y ▁of ▁Press burg ▁with ▁the ▁kingdom ▁of ▁Italy . ▁ ▁In ▁ 1 8 0 7 , ▁he ▁was ▁sent ▁to ▁Constantin ople ▁to ▁introduce ▁European ▁tact ics ▁in ▁the ▁Turkish ▁service , ▁but ▁this ▁object ▁was ▁defeated ▁by ▁the ▁death ▁of ▁Sel im ▁III ▁and ▁the ▁opposition ▁of ▁the ▁Jan iss aries . ▁ ▁Service ▁in ▁Portugal ▁On ▁F oy ' s ▁return , ▁the ▁expedition ▁against ▁Portugal ▁was ▁prepar ing . ▁He ▁received ▁a ▁command ▁in ▁the ▁art illery ▁under ▁Maj - Gen ▁Jean - And o che ▁Jun ot ▁in ▁the ▁first ▁French ▁invasion