Latvia. Altogether the forces of KOP included 24 battalions of infantry and 20 squadrons of cavalry. The soldiers of KOP were trained to combine the tactics of the army, police forces and border guards. They guarded the borders actively, not only by patrols, but also through reconnaissance, ambushes, provocation and intelligence gathering. During the first year of its existence, the KOP arrested more than 5,000 people trying to cross the border illegally. In addition, 89 armed skirmishes were fought, mainly against the bandits from the Soviet Union. To maintain the high morale and skills, the soldiers allowed into the KOP were carefully examined. Most of them were inhabitants of western voivodships, many of them were of German nationality. All volunteers had to gather experience in the regular units of the Polish Army before they were allowed in. Piłsudski's reforms (1929-35) In July 1929, the Border Defence Corps was reorganised. Six additional regiments were created, and all the existing units were renamed. Each brigade was attached to part of the Polish border which was further divided into battalion areas organised around small forts along the border. In turn, each of the battalions commanded several smaller strongholds and outposts organised by companies. All the rear troops (including the engineers, artillery and cavalry) formed the second line of the defence and were to be used as a mobile reserve. The brigades were given new names, after the area they were stationed in: Grodno Wilno Nowogródek Polesie Wołyń Podole The newly created regiments were named as follows: Głębokie Wołożyn Wilejka Suwałki Sarny Czortków Modernisation (1937-39) In early 1937 the organisation was modified. Wilno, Nowogródek and Wołyń brigades were disbanded and reorganised into three regiments: Wilno Snów Zdołbunów "Czortków" regiment was also disbanded and split onto two separate battalions ("Wilejka" and "Berezwecz"). Also, several new units were created and were pressed into the existing structure. After 1937 the KOP had 3 brigade headquarters and 7 regiments. It was composed of 32 battalions of infantry and 21 squadrons of cavalry. As the war was nearing and the crisis in Czechoslovakia exposed the Polish southern border to enemy threat, in 1939 two additional regiments were created. Those were 1st and 2nd KOP Infantry Regiments "Karpaty", each composed of two battalions of infantry (named "Skole", "Delatyn", "Komańcza" and "Dukla"). Soon three additional mountain infantry brigades were formed ("Sanok", "Nowy Sącz", "Sucha") as well as the area command in