In the 15th century, to be more precise, in 1420, Split was occupied by Venetians who recognized certain privileges to it. They ruled the city for 377 years (until 1797). In the 15th and the 16th century, marked by the spirit of Renaissance, Diocletian’s Palace became subject of interest of mariners, humanists, architects and travel writers so that there are numerous data from this period.
Economic development from the medieval free municipality was kept through the first two centuries of Venetian rule. In the cultural life of the city of Split humanists, writers, artists and builders are significant. Bernard of Split, the Franciscan from the Monastery of St. Francis published his lectionary in 1495 which is the oldest Latin-script book in Croatian language.
Marko Marulic wrote his 'Judita (Judith)', the oldest croatian literary work.
Famous artists from that period are Blaz Jurjev Trogiranin and Dujam Vuskovic, and builders and sculptors Juraj Dalmatinac and Bonino of Milan. and little later Albanian master Andrea Alessi and Nicholas of Florence.
The new defensive system is from the 16th century, and the construction of warehouse and toilet complex in the port southeast of the Palace-Lazaretto begins.
In the 17th century with the increasing threat of the Ottomans an even greater emphasis was given to the defense. Two defensive fortification systems were built. East of the city, fortresses were built in two strategically important positions - Gripe, to defend Split from the northeast, Bacvice to defend the southeast access to the port. This defensive system was completed in 1666.
However, as far as the other parts of the County are concerned, the situation is different. In the 12th century, after the weakening of Byzantium and decline of its political power, Venice became rival to Croatian-Hungarian kings and fought them for dalmatian cities and their hinterland. During the 12th and 13th century Hungarian-Croatian rulers often conquered and lost Hum (Imotska krajina then became a part of that area).
Dalmatian cities fought among themselves for the successor of King Bela Stephen VI (1270 - 1272), and the situation became even worse in 1272 at the time of Ladislaus III when Dalmatia was under the protectorate of King Charles of Naples. The Subices, Croatian aristocrats, especially viceroy Pavao, took advantage of these dynastic riots. He was the coastal viceroy (1275) and in 1283 he became Croatian viceroy. During the dynastic struggle between Andrew III, the last of the Arpad dynasty and Charles Martel of Anjou, viceroy Pavao Subic got a present from Charles - Dalmatia and Croatia. In order to win Pavao for himself and to keep him from the Anjou, King Andrew bequeathed him Dalmatia and Croatia. He also bequeathed him the viceroy' s honour. Viceroy Pavao ruled the entire Croatia. In 1299 Pavao became the Lord of Bosnia. Thus Pavao ruled a large country (just like Croatia in the time of native Croatian rulers). Pavao made his brother Mladen I Bosnian Viceroy, and his son Mladen II Duke of three fields and the whole of Hum (there is Imotska krajina there as well). After the death of Mladen I in 1304, Viceroy Pavao made his eldest son Mladen II the Viceroy of Bosnia. After Pavao's death in 1312, his son Mladen II, the Viceroy of Bosnia succeeded him as Viceroy. In a document dated April 10th, 1318, Mladen is called 'Viceroy of Croats and Bosnia and main lord of Hum'. In order to take care of the situation in Bosnia Mladen made Stjepan II Kotromanic, the son of Stjepan I Kotromanic (who was the Viceroy of Bosnia), the Viceroy of Bosnia.
After the death of Pavao Subic, the envious Croatian aristocracy, first of all the Nelipices, rose against his son and heir. They were joined by his brother Pavao as well as the Venetians and Hungarian-Croatian King Charles Robert, whose goal was to strengthen the central royal authority. Bosnian lords, the Hrvatinices and Stjepan II Kotromanic took his side. The King recognized his authority in Bosnia, Hum and Dalmatia from the Cetina to Dubrovnik as a reward for his services. Stjepan II Kotromanic relied on the heretics during his rule in Bosnia, because they had a big influence on the people. This is way many Catholics escaped his rule and the Bishop of Makarska ran away to Omis.
The Bosnian heresy of Bogomilism spread across Imotska krajina as well in the time of Stjepan II Kotromanic. On the northeastern boarder of Imotska krajina (County) there is Ledinac where there was a house of Bosnian Christians who were caring for the followers of the Bogomile Church in the former parish of Imotski.
Standing stones of Imotska krajina have their own characteristics that distinguish them from the standing stones in the neighbouring town of Hum (Herzegovina). The years on the standing stones of Imotski parish are marked with numbers. This does not exist in Bosnian standing tombstones, but the years are mentioned following the years of the rule of a Viceroy. Standing stones of Imotski vanished at the turn of the 16th century, which means after the fall to the Ottomans. Standing stones are typical of our people, since such tombstones do not exist in any other country, not even in Bulgaria, where Bogomilism started. Standing stones are tombstones, made of local limestone with relief figures of men, women, horsemen, stars, crosses... There are simple and complex ones.The simple ones are made of a single and complex ones of two blocks of stone. In complex standing stones the lower stone lies horizontally, and the second stone is placed on it in the shape of a sarcophagus. The first stone covers the grave, and the second one is decoration. The greatest number of standing stones can be found in Berinovac, above Krivodol, in Cista, Zagvozd, Lovrec. there is a popular belief that bad weather will destroy everything if standing stones are touched. Thus has this popular belief preserved the stones from destruction through the centuries. The standing stones of Imotski originate from the Middle Ages. Most of them are from the 14th and the 15th century. Until his death (1382). Ludovic rules all Croatian lands, including Imotska krajina which he got from Stjepan Tvrtko, and before that from his father-in-law Stjepan II Kotromanic. After Ludovic' s death riots and rebellions started in Croatia. Croats did not recognize the authority of his wife Elizabeth and daughter Mary. They rose up in arms led by Horvat brothers, Bishop Ivanis, Viceroy Pavao and Ivan of Palizina, prior of the monastery of Vrana. Croatian rebels received support from Bosnian King Tvrtko, who had already been crowned king of Bosnia and Serbia. During these bloody battles Tvrtko won Croatian lands (1387), among them Imotska krajina. When Split, Trogir, Sibenik and the islands of Brac, Hvar and Korcula surrendered to Tvrtko in 1390 he declared himself king of Croatia and Dalmatia.
Soon after the death of Stjepan Tvrtko in 1391 his heirs - Bosnian rulers lost significance in the struggles for the throne. Until the fall to the Turks these areas would alternately come under the rule of king Sigismund, Ladislaus of Naples and Bosnian kings and their nobles. The strongest and most important nobleman in this area at that time was the Bosnian Duke Hrvoje Vukcic Hrvatinic, duke of Split. Hrvoje became duke of Split in 1403. He dwelt with his wife from the Nelipic family in Imotski. In the time of King Stjepan Dabisa, who succeeded Tvrtko to the Bosnian throne, Hrvoje Vukcic and his brother-in-law Ivanis Nelipic had the last word in Croatian and Bosnian parts. Dabisa was succeeded to the Bosnian throne by his wife Jelena Gruba in 1395, while Queen Mary also died. After the death of Queen Mary, her husband, King Sigismund was busy with his duties in Bohemia and Germany, and payed little attention to Hungary and Croatia. In addition to this, his dissolute life caused resistance against him. In 1403 Ladislaus of Naples was crowned King of Hungary, Croatia and Dalmatia in Zadar. After the coronation Ladislaus left Dalmatia, making Hrvoje Vukcic Hrvatinic his chief governor in Hungary, Croatia and Dalmatia as well as the duke of Split. Thus Hrvoje became actual ruler: he minted money, had court, sent and received emissaries.
Ladislaus sold Zadar, NoviTown, Vrana and the island of Pag with full rights to the whole of Dalmatia for 100,000 ducats to Venice (July 9th, 1409). From this time on destiny of Dalmatia took a different course from that of the other parts of Croatia, all the way to the newer age.
In the battles between Sigismund and Venice Sigismund renounced areas that were annexed by the Venetians for the shameful sum of 10,000 ducats, and pledged almost all of Croatia for 45, 000 ducats to the Frankopans. Thus much of Dalmatia belonged to the Venetians, and the second part from the Cetina to the Neretva became a part of the Bosnian state together with four old Croatian districts of Glamoc, Livno, Duvno and Imota. After the death of Hrvoje Vukcic Hrvatinic most of his estates, together with Imotski, were inherited by his brother-in-law Ivanis Nelipic.
By the end of May of 1463 numerous and strong Ottoman army led by Sultan Muhammad II conquered the whole of Bosnia. That same year the Ottomans invaded the territory of Hum, but they failed to take it, so they plundered the fertile plains and fields around Ljubuski and Imotski. Vrgorac fell to the Ottomans in 1477.
In Croatia, struggles for power among the Croatian viceroys, King of Bosnia, who had already recognized the Ottoman government and his lords took place. In 1404 during these struggles Imotska krajina (County), which at the time was part of Hum came under the authority of Sandalj Hranic, one of the most powerful nobles from Hum, and afterwards his nephew Stjepan Vukcic Kosaca (1435-1466). Stjepan Vukcic was cunning and deceitful, but capable. He ruled Hum (Herzegovina) where there is Imotski, sometimes as a Turkish vassal, and sometimes as a friend of the Venetian Republic. In 1448, wanting all his estates to be independent, he made himself a duke (Herceg). His land was named Herzegovina after that title.
Disputes and quarrels between King Matthias, Duke Vlatko and the inhabitants of Dubrovnik about debts and the maintenance of the army were used by the Ottomans who often broke into, pillaged and looted parts of Herzegovina. Croats suffered tremendously in the Krbavsko field near Udbina in 1493. Historians do not mention the year Imotski fell to the Ottomans. There are those who believe that Imotska krajina fell in 1463, the same year as Bosnia, while others believe that it happened in 1482, the same year as Herzegovina. The historical sources state the year 1503 when Imotski was already under the Ottoman authority. In 1503 Vladislav II, successor to Matthias Corvinus. signed the truce with the Sultan Bayezid reaching agreement that borders remained as before the war, i.e. November 2nd, 1501. The Treaty says ‘… Herzegovina with its cities as well as the neighbouring cities of Prolozac and Imotski is left to the Sultan Bayezid.' Meaning that Prolozac and Imotski were under the Ottoman authority even before the beginning of the war (1501).
Sinj was conquered by the Ottomans in 1516.