In 185 BC,the last Mauryan Emperor was killed by one of his Brahmin generals and thus began the Shunga dynasty. The carving of chambers called chaityas, into living stone/hill-sides reached it's zenith during this period, with the construction of elaborate and complex halls, generally with only one window for light. These spectacular examples of giant sculptures were painstakingly cut only by human labour, to serve as meditational retreats resembling caves, into the escarpments of Western Ghats in present day Maharashtra.  Although the Shungas' reign of 112 years saw the decline of Buddhism as the Imperial religion, yet the earliest amongst these chaityas is the Buddhist chaitya hall at Bhaja, dating from the middle of second century BC. Surrounding the expected feature of the stupa is a sculpted hall made to imitate a wooden building in structure and unexpectedly many non Buddhist reliefs are also seen in a side porch within this great chaitya. Next to the chaitya as in all such chaityas are the viharas or the monasteries, cut deeper into the stone to accommodate the monks, to afford them close proximity to their revered stupa for meditation and rituals. The greatest example of  these rock cut chaityas is at Karli, carved around second century AD, though attributed to the Andhra dynasty. It features a stupa, a simple hemispherical mound in a nave, which is approached and surrounded by a row of 37 columns with carved capitals. Also carved on either side of the entrance are the donors' figures and the ever favoured Indian yaksha and yakshi couple, by now called mithuna, symbolic of fertility. Inside the Karli chaitya, an ingenius trick focusses the light coming from the window gently onto the stupa giving it the impression of a sacred enlightenment in the heart of a mountain.The most elaborately carved example as yet of the Shunga monuments is the Bharhut, which was erected when the stupas had  evolved as major religious structures. The one at Bharhut, located South-West of Allahabad, is surrounded by a stone fence with four luxuriously carved gates. Both the gates and the elaborate enclosures defining the stupa are carved in shallow relief and resemble the now lost wooden predecessors from which they must have evolved. These reliefs are  veritable Buddhist 'libraries' depicting the previous lives of the Buddha called the jatakas and the important events in his life as shakyamuni, although the Buddha himself is never shown directly. He is depicted now by a wheel symbolizing the first sermon of the Law, now by a pair of footprints, by the Bodhi tree, a rider less horse symbolizing his departure from his palace or an umbrella over a vacant space etc. The events and stories  however, often lack continuity as the patrons or donors kept changing, though as a norm monuments of such scale were commissioned by a single royal patron. Also stationed on the gateways of the Bharhut stupa are the yaksha and yakshi, blessing those who pass from beneath, with protection and fertility. Bharhut is one of India's earliest and most significant monument.During their century long reign, the Shungas were mostly involved in warfare, countering the invading Bacteria Greeks left over from Alexander's retreating armies, the Kalingas smarting from their defeat at Ashoka's hand and the barbaric nomadic tribes from the Steppes, the Scythians, followed by the Yueh-Chi (later to be called Kushans).