Here's your 10-point cheatsheet to this big story:
Mr Thackeray was Maharashtra Chief Minister before Mr Shinde rebelled and took over the post in June last year. Both factions have been fighting to keep the party's original name and election symbol to represent the "real" Shiv Sena.
The crisis started in June last year with the exodus of nearly 50 MLAs from the previous Maha Vikas Aghadi alliance of the Sena, Congress and the Nationalist Congress Party.
Mr Shinde and some 40 Sena MLAs along with 10 others first dashed to BJP-ruled Gujarat by road. From there, they flew in a chartered flight to Assam, another BJP ruled state.
Days later, it became clear Mr Thackeray enjoyed the support of only 15-odd MLAs loyal to him. He resigned thereafter.
In late June 2022, Mr Shinde returned to Mumbai from Assam with the rebel MLAs - even took a short break in Goa - and claimed he has the BJP's support to form government.
The Maha Vikas Aghadi government fell and Mr Shinde became the Chief Minister, amid rumblings that BJP leader and former Chief Minister Devendra Fadnavis had been hoping to return to the top post.
A new problem came up - which of the two factions would use the election symbol and the name of the party founded by Bal Thackeray, the father of Uddhav Thackeray.
The matter eventually reached the Supreme Court. Team Thackeray blamed Mr Shinde and the BJP for engineering a takeover and challenged them to face fresh election. Mr Thackeray's faction said they represented the "real Shiv Sena".
Mr Shinde's camp, however, said they had the support of a majority of Sena MLAs and whoever in the party has their support should lead the Sena.
Today, the Election Commission allowed Mr Shinde's faction to use the name "Shiv Sena" and the party's symbol, although the Supreme Court is yet to give its verdict on a request by Team Thackeray to disqualify 16 Sena MLAs among the ones who revolted against him last year. Team Thackeray said they will challenge the Election Commission's decision in the Supreme Court.
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