Unlock buildings with a historic event

hello to all my first post is about historic events in mtw2...i want to make a hist event that unlock 4 buildings(casa templaria;grande_casa templaria;priorado;grande_priorado....and this buildings will train some units of templars and crusaders,but only after the event occurs...the event wil be " templars arrive to Portugal" and will be only to Portugal....i can make the buildings but how can i do the event to fire with event picture and everything?Can you help guys??....sorry the big post

exp_desc_buildings

building Ordem_dos_Templarios
{
levels casa_templaria Grande_casa_templaria Priorado Grande_priorado
{
casa_templaria requires factions { portugal, }
{
convert_to 0
capability
{
recruit_pool "Templar Crossbowmen" 1 0.7 6 0 requires factions { portugal, }
recruit_pool "Irmaos Templarios" 1 0.5 4 0 requires factions { portugal, }
}
material wooden
construction 1
cost 2000
settlement_min city
upgrades
{
Grande_casa_templaria
}
}
Grande_casa_templaria city requires factions { portugal, }
{
convert_to 1
capability
{
recruit_pool "Templar Crossbowmen" 1 0.7 6 0 requires factions { portugal, }
recruit_pool "Irmaos Templarios" 1 0.5 4 0 requires factions { portugal, }
recruit_pool "Crusader Sergeants" 1 0.5 4 0 requires factions { portugal, }
}
material wooden
construction 2
cost 3000
settlement_min large_city
upgrades
{
Priorado
}
}
Priorado city requires factions { portugal, }
{
convert_to 2
capability
{
recruit_pool "Templar Crossbowmen" 1 0.7 6 0 requires factions { portugal, }
recruit_pool "Irmaos Templarios" 1 0.5 4 0 requires factions { portugal, }
recruit_pool "Crusader Sergeants" 1 0.5 4 0 requires factions { portugal, }
}
material wooden
construction 2
cost 3000
settlement_min huge_city
upgrades
{
Grande_priorado
}
}
Grande_priorado city requires factions { portugal, }
{
convert_to 3
capability
{
recruit_pool "Templar Crossbowmen" 1 0.7 6 0 requires factions { portugal, }
recruit_pool "Irmaos Templarios" 1 0.5 4 0 requires factions { portugal, }
recruit_pool "Crusader Sergeants" 1 0.5 4 0 requires factions { portugal, }
recruit_pool "Dismounted Templar Knights" 1 0.5 4 0 requires factions { portugal, }
}
material wooden
construction 3
cost 4000
settlement_min huge_city
upgrades
{
}
}
}
plugins
{
}
}

the exp_buildings

{Ordem_dos_Templarios_name}Ordem dos Templarios
{casa_templaria}casa_templaria
{casa_templaria_desc}DO NOT TRANSLATE
{casa_templaria_desc_short}DO NOT TRANSLATE
{casa_templaria_southern_european}casa templaria
{casa_templaria_southern_european_desc}A casa templaria
{casa_templaria_southern_european_desc_short}A casa templaria
{Grande_casa_templaria}Grande_casa_templaria
{Grande_casa_templaria_desc}DO NOT TRANSLATE
{Grande_casa_templaria_desc_short}DO NOT TRANSLATE
{Grande_casa_templaria_southern_european}Grande casa templaria
{Grande_casa_templaria_southern_european_desc}A Grande casa templaria
{Grande_casa_templaria_southern_european_desc_shor t}A Grande casa templaria
{Priorado}Priorado
{Priorado_desc}DO NOT TRANSLATE
{Priorado_desc_short}DO NOT TRANSLATE
{Priorado_southern_european}Priorado
{Priorado_southern_european_desc}o Priorado
{Priorado_southern_european_desc_short}o Priorado
{Grande_priorado}Grande_priorado
{Grande_priorado_desc}DO NOT TRANSLATE
{Grande_priorado_desc_short}DO NOT TRANSLATE
{Grande_priorado_southern_european}Grande priorado
{Grande_priorado_southern_european_desc}o Priorado
{Grande_priorado_southern_european_desc_short}o Priorado

this is the buildings.....hope you can help...thanks in advance