Complex sentence: He was busy meanwhile with the archaeological and historical notes that ultimately developed into the "Annals of Dunfermline", and he secured in 1856 the recognition of Dunfermline as a city.
Split into simpler sentences: He was busy meanwhile with the archaeological and historical notes that ultimately developed into the "Annals of Dunfermline". In 1856 he achieved the recognition of Dunfermline as a city.