However, the international obligations, of a declared policy of neutrality, were inconsistent with the large number of British combatants to fight from the United Kingdom and its colonies, against Spain's own colonies in South America. Before 1817 a few British had participated in early phases of the struggle in different parts of America, mostly isolated, but relevant actions, such as in the Rio de la Plata. Nevertheless the systematic recruitment in Britain began in April 1817, to fight for Simón Bolívar. The circumstances were very favourable, with the help of Venezuelan agents and adventurers such as Gregor McGregor, British officers and sergeants were recruited forming their own regiments.